-----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 2001,MIC-CLEAR Originator-Name: webmaster@www.sec.gov Originator-Key-Asymmetric: MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB MIC-Info: RSA-MD5,RSA, VkzGVEOHQm7Akpmiy83ZT3nxHWkAkH+K80YKMpaqAhwZoG6n6lK3m3i62TZXfKQy O7dZCxAWl7UKS0kss82nZA== 0000912057-97-000542.txt : 19970110 0000912057-97-000542.hdr.sgml : 19970110 ACCESSION NUMBER: 0000912057-97-000542 CONFORMED SUBMISSION TYPE: SC 13D PUBLIC DOCUMENT COUNT: 5 FILED AS OF DATE: 19970109 SROS: NASD SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: STRATEGIC DIAGNOSTICS INC/DE/ CENTRAL INDEX KEY: 0000911649 STANDARD INDUSTRIAL CLASSIFICATION: MISCELLANEOUS CHEMICAL PRODUCTS [2890] IRS NUMBER: 561581761 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13D SEC ACT: 1934 Act SEC FILE NUMBER: 005-47761 FILM NUMBER: 97503259 BUSINESS ADDRESS: STREET 1: 128 SANDY DR CITY: NEWARK STATE: DE ZIP: 19713 BUSINESS PHONE: 3024566789 MAIL ADDRESS: STREET 1: 128 SANDY DR CITY: NEWARK STATE: DE ZIP: 19713 FORMER COMPANY: FORMER CONFORMED NAME: ENSYS ENVIRONMENTAL PRODUCTS INC /DE/ DATE OF NAME CHANGE: 19930907 FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: DSV PARTNERS IV CENTRAL INDEX KEY: 0001007713 STANDARD INDUSTRIAL CLASSIFICATION: [] FILING VALUES: FORM TYPE: SC 13D BUSINESS ADDRESS: STREET 1: 221 NASSAU STREET CITY: PRINCETON STATE: NJ ZIP: 08542 BUSINESS PHONE: 6099246420 SC 13D 1 SCHEDULE 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 Strategic Diagnostics Inc. - ------------------------------------------------------------------------------- (Name of Issuer) Common Stock, par value $.01 per share - ------------------------------------------------------------------------------- (Title of Class of Securities) 862700101 - ------------------------------------------------------------------------------- (CUSIP Number) Morton Collins, DSV Partners IV, 221 Nassau Street, Princeton, NJ 08542 (609)924-6420 - ------------------------------------------------------------------------------- (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) December 30, 1996 - ------------------------------------------------------------------------------- (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(b)(3) or (4), check the following box . NOTE: Six copies of this statement, including all exhibits, should be filed with the Commission. SEE Rule 13d-1(a) for other parties to whom copies are to be sent. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). Page 1 --- SCHEDULE 13D CUSIP NO. 862700101 PAGE 2 - ---------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON DSV Partners IV - ---------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) / / (b) / / - ---------------------------------------------------------------------------- 3 SEC USE ONLY - ---------------------------------------------------------------------------- 4 SOURCE OF FUNDS* OO - ---------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS / / REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) - ---------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION New Jersey - ---------------------------------------------------------------------------- 7 SOLE VOTING POWER NUMBER OF 1,297,177 SHARES -------------------------------------------------------------- BENEFICIALLY 8 SHARED VOTING POWER OWNED BY EACH N/A REPORTING -------------------------------------------------------------- PERSON 9 SOLE DISPOSITIVE POWER WITH 1,297,177 -------------------------------------------------------------- 10 SHARED DISPOSITIVE POWER N/A - ---------------------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,297,177 - ---------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) / / EXCLUDES CERTAIN SHARES* - ---------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.1% - ---------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* PN - ---------------------------------------------------------------------------- SEE INSTRUCTIONS BEFORE FILLING OUT! SCHEDULE 13D STATEMENT ITEM 1. SECURITY AND ISSUER. This statement relates to the shares of Common Stock, par value $.01 per share (the "Common Stock") of Strategic Diagnostics Inc., a Delaware corporation (the "Issuer"). The principal executive offices of the Issuer are located at 128 Sandy Drive, Newark, Delaware 19713. ITEM 2. IDENTITY AND BACKGROUND. DSV Partners IV is a New Jersey limited partnership. Its office is located at 221 Nassau Street, Princeton, New Jersey 08542. DSV Partners IV invests in technology based companies. The sole general partner of DSV Partners IV is DSV Management Ltd. which is a New Jersey limited partnership located at 221 Nassau Street, Princeton, New Jersey 08542. Set forth below is the name and address of each General Partner of DSV Management Ltd.: James R. Bergman DSV Partners IV 1920 Main Street Suite 820 Irvine, CA 92614 Morton Collins DSV Partners IV 221 Nassau Street Princeton, NJ 08542 John Park DSV Partners IV 221 Nassau Street Princeton, NJ 08542 John K. Clarke DSV Partners IV 221 Nassau Street Princeton, NJ 08542 Page 3 --- None of DSV Partners IV, DSV Management Ltd. or any General Partner of DSV Management Ltd. has been convicted in a criminal proceeding (excluding traffic violations and similar misdemeanors) during the past five years, or have been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of or prohibiting activities subject to, federal or state securities laws or finding any violation of such laws. ITEM 3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION. DSV Partners IV was the beneficial owner of 1,463,980 shares of Series A Convertible Preferred Stock of Strategic Diagnostics Inc. ("SDI") and 275,000 immediately exercisable warrants to purchase shares of Common Stock of SDI. On December 30, 1996, SDI merged with and into EnSys Environmental Products, Inc. ("EnSys"). The surviving corporation, EnSys, was subsequently renamed Strategic Diagnostics Inc. Each share of SDI common and preferred stock was converted into .7392048 shares of the Issuer. Each warrant to purchase SDI common stock was converted into .7818026 warrants to purchase shares of the Issuer's common stock. Each share of Series A Convertible Preferred Stock of the Issuer is currently convertible into one share of Common Stock of the Issuer. Accordingly, through its ownership of Series A Convertible Preferred Stock, DSV Partners IV beneficially owns 1,082,181 shares of Common Stock. Moreover, through its ownership of warrants to purchase Common Stock, DSV Partners IV beneficially owns an additional 214,996 shares of Common Stock, for an aggregate of 1,297,177 shares beneficially owned. Page 4 --- ITEM 4. PURPOSE OF TRANSACTION. DSV Partners IV acquired the shares of the Issuer for investment purposes. DSV Partners IV will monitor market conditions and pursue sales from time to time although there can be no assurance of the total number of shares to be sold. DSV Partners IV may from time to time acquire additional securities (through one or more market purchases or purchases in private transactions) or dispose of all or a portion of the securities which it now owns or hereafter may acquire (through one or more market or private transactions or distributions to partners in accordance with the partnership agreement). Except as set forth above, DSV Partners IV does not have any present plans or proposals which relate to or would result in any of the actions described in paragraphs (a) through (j) of Item 4 of Schedule 13D. ITEM 5. INTEREST IN SECURITIES OF THE ISSUER. DSV Partners IV beneficially owns: (i) 1,082,181 shares of Common Stock through its ownership of Series A Convertible Preferred Stock and (ii) 214,996 shares of Common Stock through its ownership of warrants to purchase Common Stock, for an aggregate of 1,297,177 shares of Common Stock beneficially owned, which equals 9.1% of the outstanding shares of Common Stock of the Issuer. ITEM 5(B). Number of shares as to which DSV Partners IV has: sole power to vote or to direct the vote: 1,297,177 shared power to vote or to direct the vote: None sole power to dispose or to direct the disposition: 1,297,177 shared power to dispose or to direct the disposition: None Page 5 --- ITEM 5(C). None of DSV Partners IV, DSV Management Ltd. or any General Partner of DSV Management Ltd. has been a party to any transaction in the Common Stock during the sixty day period ending on the date of this Statement on Schedule 13D, other than the transactions described herein. ITEM 5(D). Not applicable. ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER. DSV Partners IV has signed a "lock-up" agreement with the Issuer, pursuant to which DSV has agreed not to sell or transfer its shares of the Issuer's Common or Preferred Stock for a period of six months from the date of the merger between SDI and the Issuer. DSV Partners IV has also entered into a Registration Rights Agreement with the Issuer, dated December 30, 1996, which provides for (i) certain demand registration rights and (ii) the right to require the Issuer to include Common Stock owned by DSV Partners IV in any other registration of Issuer's Common Stock. The terms of the Series A Convertible Preferred Stock are set forth in the Fourth Amended and Restated Certificate of Incorporation of the Issuer. ITEM 7. MATERIAL TO BE FILED AS EXHIBITS. Exhibit 1 - Letter Agreement dated December 30, 1996 between Issuer and DSV. Exhibit 2 - Registration Rights Agreement dated December 30, 1996 between Issuer and certain holders of Issuer's Common Stock. Exhibit 3 - Warrants W-12/30/96 - A through G, issued by EnSys in favor of DSV. Exhibit 4 - Fourth Amended and Restated Certificate of Incorporation of the Issuer. Page 6 --- SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. DSV PARTNERS IV Dated: January 8, 1997 By: DSV MANAGEMENT LTD. its General Partner By: Morton Collins a General Partner /s/ Morton Collins -------------- Page 7 --- EX-1 2 EXHIBIT 1 EXHIBIT 1 December 30, 1996 EnSys Environmental Products, Inc. 4222 Emperor Boulevard Durham, North Carolina 27703 Dear Ladies and Gentlemen: In consideration of the benefit to the stockholders of Strategic Diagnostics Inc. ("Company") of the merger of the Company with and into EnSys Environmental Products, Inc. ("EnSys"), pursuant to the Agreement and Plan of Merger between the Company and EnSys dated as of October 11, 1996, and for other good and valuable consideration, the receipt of which is hereby acknowledged, the undersigned hereby agrees that, without the prior written consent of EnSys, he or she will not sell, contract to sell, or otherwise dispose of for value, any of the EnSys Preferred Stock, Common Stock or any security exchangeable or exercisable for or convertible into EnSys Common Stock, beneficially owned by the undersigned until the date which is six (6) months from the date hereof; provided that the undersigned may pledge or cause to be pledged any or all of such shares or other securities in bona fide loan transactions with established financial lending institutions. DSV PARTNERS IV By: DSV MANAGEMENT LTD., its General Partner By: Morton Collins, a General Partner /s/ Morton Collins ----------------------------- EX-2 3 EXHIBIT 2 EXHIBIT 2 December 30, 1996 To each of the Original Holders listed on the signature pages hereto Dear Sirs: This agreement is made in connection with the Agreement and Plan of Merger, dated as of October 11, 1996 (the "Merger Agreement") by and between Strategic Diagnostics Inc., a Delaware corporation ("SDI") and EnSys Environmental Products, Inc., a Delaware corporation (the "Company"), pursuant to which SDI shall be merged with and into the Company in accordance with the applicable provisions of the Delaware General Corporation Law and the terms of the Merger Agreement. The merger consideration received by the Original Holders (as hereinafter defined) includes, common stock, par value $.01, of the Company (the "Common Stock"), Series A Convertible Preferred Stock (the "Preferred Stock"), par value $.01, of the Company that is convertible into shares of Common Stock, and warrants (the "Warrants") to purchase shares of Common Stock. The Company covenants and agrees with each of you (the "Original Holders") as follows: 1. Certain Definitions. As used in this Agreement, the following terms shall have the following respective meanings: "Commission" shall mean the Securities and Exchange Commission, or any other federal agency at the time administering the Securities Act. "Common Stock" shall mean the Common Stock, $0.01 par value, of the Company, as constituted as of the date of this Agreement. "Conversion Shares" shall mean shares of Common Stock issued upon conversion of the Preferred Shares, together with any shares of Common Stock issued on or with respect to other Conversion Shares by way of a stock split, stock dividend or the like. "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended, or any similar federal statute, and the rules and regulations of the Commission thereunder, all as the same shall be in effect at the time. "Perkin-Elmer Shares" shall mean 1,308,724 shares of Common Stock issued pursuant to the Merger Agreement to The Perkin-Elmer Corporation. "Preferred Shares" shall mean an aggregate of 2,164,362 shares of Preferred Stock issued pursuant to the Merger Agreement to DSV Partners IV, Edison Venture Fund II, L.P. and Edison Venture Fund II-Pa, L.P. "Registration Expenses" shall mean the expenses so described in Section 8. "Restricted Stock" shall mean the Conversion Shares, Perkin-Elmer Shares, and Warrant Shares, excluding Conversion Shares, Perkin-Elmer Shares, and Warrant Shares which (a) have been registered under the Securities Act pursuant to an effective registration statement filed thereunder and disposed of in accordance with the registration statement covering them or (b) are eligible for public sale without limitation as to amount pursuant to Rule 144 or Rule 145 under the Securities Act. "Securities Act" shall mean the Securities Act of 1933, as amended, or any similar federal statute, and the rules and regulations of the Commission thereunder, all as the same shall be in effect at the time. "Selling Expenses" shall mean the expenses so described in Section 8. "Transfer" shall include any disposition of any Preferred Shares, Perkin-Elmer Shares, Conversion Shares and Warrant Shares or of any interest therein which would constitute a sale thereof within the meaning of the Securities Act. "Warrant Shares" shall mean shares of Common Stock issued upon exercise of the Warrants, together with any shares of Common Stock issued on or with respect to other Warrant Shares by way of stock split, stock dividend or the like. 2. Restrictive Legend. The Preferred Shares, Perkin-Elmer Shares, Conversion Shares and Warrant Shares shall not be transferable, except upon the conditions specified in Sections 2 and 3 hereof, which conditions are intended to ensure compliance with the provisions of the Securities Act in respect of the Transfer thereof. Each certificate representing Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares shall, except as otherwise provided in this Section 2 or in Section 3, be stamped or otherwise imprinted with a legend substantially in the following form: 2 "THIS SECURITY HAS NOT BEEN REGISTERED FOR SALE UNDER THE SECURITIES ACT OF 1933 AND MAY NOT BE TRANSFERRED OR OTHERWISE DISPOSED OF EXCEPT IN COMPLIANCE WITH THAT CERTAIN REGISTRATION RIGHTS AGREEMENT, DATED DECEMBER 30, 1996 AMONG THE COMPANY AND THE SIGNATORIES THERETO AND THE SECURITIES ACT OF 1933, AS AMENDED." 3. Notice of Proposed Transfer. Prior to any proposed Transfer of any Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares (other than under the circumstances described in Sections 4 or 5), the holder thereof shall give written notice to the Company of its intention to effect such Transfer. Each such notice shall describe the manner of the proposed Transfer and, if requested by the Company, shall be accompanied by an opinion of counsel satisfactory to the Company to the effect that the proposed Transfer may be effected without registration under the Securities Act, whereupon the holder of such stock shall be entitled to Transfer such stock in accordance with the terms of its notice; provided, however, that no such opinion of counsel shall be required for a Transfer to one or more partners of an Original Holder (in the case of an Original Holder that is a partnership) or to an affiliated corporation of an Original Holder (in the case of an Original Holder that is a corporation), if, with respect to such Transfer, the transferee agrees in writing to be subject to the terms of Sections 2, 3 and 10 hereof, to the same extent as if such transferee were originally a signatory to this Agreement. Each certificate for Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares transferred as above provided shall bear the legend set forth in Section 2, except that such certificate shall not bear such legend if (i) such Transfer is in accordance with the provisions of Rule 144 (or any other rule permitting public sale without registration under the Securities Act) or (ii) the opinion of counsel referred to above is to the further effect that the transferee and any subsequent transferee (other than an affiliate of the Company) would be entitled to Transfer such securities in a public sale without registration under the Securities Act. The restrictions provided for in this Section 3 shall not apply to securities which are not required to bear the legend prescribed by Section 2 in accordance with the provisions of that Section. 4. Required Registration. (a) At any time after the date which is six (6) months from the date of this Agreement, any two (2) of the three (3) holders of Restricted Stock acting together as a group may request on two (2) separate occasions the Company to register under the Securities Act all or any portion of the shares of Restricted Stock held by such requesting holders for sale in the manner specified in such notice, provided that the shares of Restricted Stock for which registration has been 3 requested shall constitute at least the lesser of (i) 50% of the total shares of Restricted Stock originally issued to such holders, or (ii) the remaining shares of Restricted Stock held by such holders, but in any event not less than 1,500,000 shares of Restricted Stock. For purposes of this Section 4 and Sections 5, 12(a) and 12(d), the term "Restricted Stock" shall be deemed to include the number of shares of Restricted Stock which would be issuable to a holder of Preferred Shares upon conversion of all shares of Preferred Stock held by such holder at such time and the number of shares of Restricted Stock which would be issuable to a holder of Warrants upon exercise of all Warrants held by such holder at such time, provided, however, that the only securities which the Company shall be required to register pursuant hereto shall be shares of Common Stock, and provided, further, however, that, in any underwritten public offering contemplated by this Section 4 or Section 5, the holders of Preferred Shares and Warrants shall be entitled to sell such Preferred Shares and Warrants to the underwriters for conversion or exercise, respectively, and sale of the shares of Common Stock issued upon conversion thereof. Notwithstanding anything to the contrary contained herein, no request may be made under this Section 4 within 180 days after the effective date of a registration statement filed by the Company covering a firm commitment underwritten public offering in which the holders of Restricted Stock shall have been entitled to join pursuant to Section 5 and in which there shall have been effectively registered at least fifty percent (50%) of the shares of Restricted Stock as to which registration shall have been requested. (b) Following receipt of any notice under this Section 4, the Company shall immediately notify all holders of Restricted Stock from whom notice has not been received and shall use all reasonable efforts to register under the Securities Act, for public sale in accordance with the method of disposition specified in such notice from requesting holders, the number of shares of Restricted Stock specified in such notice (and in all notices received by the Company from other holders within 30 days after the giving of such notice by the Company). If such method of disposition shall be an underwritten public offering, the Company may designate the managing underwriter of such offering, subject to the approval of the holders of a majority of the shares of Restricted Stock to be sold in such offering, which approval shall not be unreasonably withheld, conditioned or delayed. The Company shall be obligated to register Restricted Stock pursuant to this Section 4 on two occasions only, provided, however, that such obligation shall be deemed satisfied only when a registration statement covering at least the lesser of (i) 50% of the total shares of Restricted Stock originally issued or (ii) 75% of the shares of Restricted Stock specified in notices 4 received as aforesaid, for sale in accordance with the method of disposition specified by the requesting holders, shall have become effective; provided, further, however, that any registration proceeding begun pursuant to this Section 4 which is subsequently withdrawn at the request of the holders of a majority of the shares of Restricted Stock requested to be registered shall count toward such two registration statements which the holders of the shares of Restricted Stock have the right to cause the Company to effect pursuant to this Section 4. (c) The Company shall be entitled to include in any registration statement referred to in this Section 4, for sale in accordance with the method of disposition specified by the requesting holders, shares of Common Stock to be sold by the Company for its own account, or any issued and outstanding shares of Common Stock to be sold by others except as and to the extent that, in the opinion of the managing underwriter (if such method of disposition shall be an underwritten public offering), such inclusion would adversely affect the marketing of the Restricted Stock to be sold. 5. Incidental Registration. If the Company at any time (other than pursuant to Section 4) proposes to register any of its securities under the Securities Act for sale to the public, whether for its own account or for the account of other security holders or both (except with respect to registration statements on Forms S-4 or another form not available for registering the Restricted Stock for sale to the public), each such time it will give written notice to all holders of outstanding Restricted Stock of its intention so to do. Upon the written request of any such holder received by the Company within 30 days after the giving of any such notice by the Company, to register any of its Restricted Stock (which request shall state the intended method of disposition thereof), the Company will use all commercially reasonable efforts (subject to the rights of any holders of securities of the Company, other than the Company, included in such registration) to cause the Restricted Stock as to which registration shall have been so requested to be included in the securities to be covered by the registration statement proposed to be filed by the Company, all to the extent requisite to permit the sale or other disposition by the holder (in accordance with its written request) of such Restricted Stock so registered. In the event that any registration pursuant to this Section 5 shall be, in whole or in part, an underwritten public offering of Common Stock, the number of shares of Restricted Stock as a group to be included in such an underwriting may be reduced (pro rata among the holders of Restricted Stock based upon the number of shares of Restricted Stock owned by such holders) if and to the extent that the managing underwriter shall be of the opinion that such inclusion would adversely affect the 5 marketing of the securities to be sold by the Company or other holder of securities of the Company. Notwithstanding the foregoing provisions, the Company may withdraw any registration statement referred to in this Section 5 without thereby incurring any liability to the holders of Restricted Stock. 6. Holdback Agreement. If the Company at any time shall register shares of Common Stock under the Securities Act (including any registration pursuant to Sections 4 and 5) for sale to the public, the Original Holders shall not sell publicly, make any short sale of, grant an option for the purchase of, or otherwise dispose of, any shares of Restricted Stock (other than those shares of Common Stock included in such registration pursuant to Sections 4 or 5) without the prior written consent of the Company for a period designated by the Company in writing to the holders of shares of Restricted Stock, which period shall not begin more than 10 days prior to the effectiveness of the registration statement pursuant to which such public offer will be made and shall not last more than 180 days after the effective date of such registration statement. 7. Registration Procedures. If and whenever the Company is required by the provisions of Sections 4 or 5 to use all reasonable efforts or all commercially reasonable efforts to effect the registration of any shares of Restricted Stock under the Securities Act, the Company will, as expeditiously as possible: (a) prepare and file with the Commission a registration statement on Form S-1 or Form S-3 if available with respect to such securities and use all reasonable efforts to cause such registration statement to become and remain effective for the period of the distribution contemplated thereby (determined as hereinafter provided) (subject, in the case of any Incidental Registration, to the rights of the Company to abandon any such registration as set forth in Section 5); (b) with respect to any registration pursuant to Section 4, prepare and file with the Commission such amendments and supplements to such registration statement and the prospectus used in connection therewith as may be necessary to keep such registration statement effective for the period specified above and comply with the provisions of the Securities Act with respect to the disposition of all Restricted Stock covered by such registration statement in accordance with the sellers' intended method of disposition set forth in such registration statement for such period; (c) furnish to each seller of Restricted Stock and to each underwriter such number of copies of the registration 6 statement and the prospectus included therein (including each preliminary prospectus) as such persons reasonably may request in order to facilitate the public sale or other disposition of the Restricted Stock covered by such registration statement; (d) use all reasonable efforts to register or qualify the Restricted Stock covered by such registration statement under the securities or "blue sky" laws of such jurisdictions as the sellers of Restricted Stock or, in the case of an underwritten public offering, the managing underwriter reasonably shall request, provided, however, that the Company shall not for any such purpose be required to qualify generally to transact business as a foreign corporation in any jurisdiction where it is not so qualified, to consent to general service of process in any such jurisdiction or submit to liability for state or local taxes where it is not otherwise liable for such taxes; (e) use all reasonable efforts to list the Restricted Stock covered by such registration statement with any securities exchange on which the Common Stock of the Company is then listed; (f) immediately notify each seller of Restricted Stock and each underwriter under such registration statement, at any time when a prospectus relating thereto is required to be delivered under the Securities Act, of the happening of any event of which the Company has knowledge as a result of which the prospectus contained in such registration statement, as then in effect, includes an untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in light of the circumstances then existing; (g) if the offering is underwritten and at the request of any seller of Restricted Stock, use all reasonable efforts to furnish on the date that Restricted Stock is delivered to the underwriters for sale pursuant to such registration: (i) an opinion, dated such date, of the counsel representing the Company for the purposes of such registration, in form and substance as is customarily given to underwriters in an underwritten public offering, addressed to the underwriters, if any, and to the seller or sellers making such request; and (ii) at the request of either the underwriters or sellers of Restricted Stock, a letter dated such date from the independent public accountants retained by the Company, addressed to the underwriters and to such seller, stating that they are independent public accountants within the meaning of the Securities Act and that, in the opinion of such accountants, the financial statements of the Company included in the registration statement or the prospectus, or any amendment or supplement 7 thereof, comply as to form in all material respects with the applicable accounting requirements of the Securities Act, and such letter shall additionally cover such other financial matters (including information as to the period ending no more than five business days prior to the date of such letter) with respect to such registration as such underwriters reasonably may request; and (h) make reasonably available for inspection by each seller of Restricted Stock, any underwriter participating in any distribution pursuant to such registration statement, and any attorney, accountant or other agent retained by such seller or underwriter, all financial and other records, pertinent corporate documents and properties of the Company, and use all reasonable efforts to cause the Company's officers, directors and employees to supply all information reasonably requested by any such seller, underwriter, attorney, accountant or agent in connection with such registration statement, in each case as and to the extent necessary to permit the sellers to conduct a reasonable investigation within the meaning of the Securities Act. To minimize disruption and expense to the Company during the course of the registration process, the sellers will act through a single law firm and a single accounting firm and will enter into confidentiality agreements with the Company in form and substance reasonably satisfactory to the Company and the sellers prior to receiving any confidential or proprietary information of the Company. For purposes of Section 7(a) and 7(b) and of Section 4(c), the period of distribution of Restricted Stock in a firm commitment underwritten public offering shall be deemed to extend until each underwriter has completed the distribution of all securities purchased by it, and the period of distribution of Restricted Stock in any other registration shall be deemed to extend until the earlier of the sale of all Restricted Stock covered thereby, or nine (9) months after the effective date thereof. In connection with each registration hereunder, the sellers of Restricted Stock will furnish to the Company in writing such information with respect to themselves and the proposed distribution by them as reasonably shall be necessary in order to assure compliance with federal and applicable state securities laws. In connection with each registration pursuant to Sections 4 or 5 covering an underwritten public offering, the Company and each seller agree to enter into a written agreement with the managing underwriter selected in the manner herein provided in such form and containing such provisions as are 8 customary in the securities business for such an arrangement between such underwriter and companies of the Company's size and investment stature. 8. Expenses. All expenses (both third party and internal) incurred by the Company in complying with Sections 4 and 5, including, without limitation, all registration and filing fees, printing expenses, fees and disbursements of counsel and independent public accountants for the Company, fees and expenses (including counsel fees) incurred in connection with complying with state securities or "blue sky" laws, fees of the National Association of Securities Dealers, Inc., transfer taxes, fees of transfer agents and registrars, costs of insurance, but excluding any Selling Expenses, are called "Registration Expenses". All underwriting discounts and selling commissions applicable to the sale of Restricted Stock, and all fees and disbursements of legal counsel for the sellers of Restricted Stock, are called "Selling Expenses". The Company will pay all Registration Expenses in connection with each registration statement under Sections 4 or 5. All Selling Expenses in connection with each registration statement under Sections 4 or 5 shall be borne by the participating sellers in proportion to the number of shares sold by each, or by such participating sellers other than the Company (except to the extent the Company shall be a seller) as they may agree. 9. Indemnification and Contribution. (a) In the event of a registration of any of the Restricted Stock under the Securities Act pursuant to Sections 4 or 5, the Company will indemnify and hold harmless each seller of such Restricted Stock thereunder, each underwriter of such Restricted Stock thereunder and each other person, if any, who controls such seller or underwriter within the meaning of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which such seller, underwriter or controlling person may become subject under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in any registration statement under which such Restricted Stock was registered under the Securities Act pursuant to Sections 4 or 5, any preliminary prospectus or final prospectus contained therein, or any amendment or supplement thereof, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse each such seller, each such underwriter and each such controlling person for any legal or other expenses reasonably incurred by 9 them in connection with investigating or defending any such loss, claim, damage, liability or action, provided, however, that the Company will not be liable in any such case if and to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission so made in conformity with information furnished by any such seller, any such underwriter or any such controlling person in writing specifically for use in such registration statement or prospectus. (b) In the event of a registration of any of the Restricted Stock under the Securities Act pursuant to Sections 4 or 5, each seller of such Restricted Stock thereunder, severally and not jointly, will indemnify and hold harmless the Company, each person, if any, who controls the Company within the meaning of the Securities Act, each officer of the Company who signs the registration statement, each director of the Company, each underwriter and each person who controls any underwriter within the meaning of the Securities Act, against all losses, claims, damages or liabilities, joint or several, to which the Company or such officer, director, underwriter or controlling person may become subject under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in the registration statement under which such Restricted Stock was registered under the Securities Act pursuant to Sections 4 or 5, any preliminary prospectus or final prospectus contained therein, or any amendment or supplement thereof, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse the Company and each such officer, director, underwriter and controlling person for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability or action, provided, however, that such seller will be liable hereunder in any such case if and only to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with information pertaining to such seller, as such, furnished in writing to the Company by such seller specifically for use in such registration statement or prospectus, and provided, further, however, that the liability of each seller hereunder shall not in any event exceed the proceeds received by such seller from the sale of Restricted Stock covered by such registration statement. 10 (c) Promptly after receipt by an indemnified party hereunder of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party hereunder, notify the indemnifying party in writing thereof, but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to such indemnified party other than under this Section 9 and shall only relieve it from any liability which it may have to such indemnified party under this Section 9 if and to the extent the indemnifying party is prejudiced by such omission. In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate in and, to the extent it shall wish, to assume and undertake the defense thereof with counsel satisfactory to such indemnified party, and, after notice from the indemnifying party to such indemnified party of its election so to assume and undertake the defense thereof, the indemnifying party shall not be liable to such indemnified party under this Section 9 for any legal expenses subsequently incurred by such indemnified party in connection with the defense thereof other than reasonable costs of investigation and of liaison with counsel so selected, provided, however, that, if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that there may be reasonable defenses available to it which are different from or additional to those available to the indemnifying party or if the interests of the indemnified party reasonably may be deemed to conflict with the interests of the indemnifying party, the indemnified party shall have the right to select a separate counsel and to assume such legal defenses and otherwise to participate in the defense of such action, with the expenses and fees of such separate counsel and other expenses related to such participation to be reimbursed by the indemnifying party as incurred. (d) In order to provide for just and equitable contribution to joint liability under the Securities Act in any case in which either (i) any holder of Restricted Stock exercising rights under this Agreement, or any controlling person of any such holder, makes a claim for indemnification pursuant to this Section 9 but it is judicially determined (by the entry of a final judgment or decree by a court of competent jurisdiction and the expiration of time to appeal or the denial of the last right of appeal) that such indemnification may not be enforced in such case notwithstanding the fact that this Section 9 provides for indemnification in such case, or (ii) contribution under the Securities Act may be required on the part of any such selling holder or any such controlling person in circumstances for which indemnification is provided under this Section 9; then, and in 11 each such case, the Company and such holder will contribute to the aggregate losses, claims, damages or liabilities to which they may be subject (after contribution from others) as is appropriate to reflect the relative fault of the Company and such holder in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities, as well as the relative benefit received by the Company and such holder as a result of the offering in question, it being understood that the parties acknowledge that the overriding equitable consideration to be given effect in connection with this provision is the ability of one party or the other to correct the statement or omission which resulted in such losses, claims, damages or liabilities, and that it would not be just and equitable if contribution pursuant hereto were to be determined by pro rata allocation or by any other method of allocation which does not take into consideration the foregoing equitable considerations; provided, however, that, in any such case, (A) no such holder will be required to contribute any amount in excess of the public offering price of all such Restricted Stock offered by it pursuant to such registration statement; and (B) no person or entity guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) will be entitled to contribution from any person or entity who was not guilty of such fraudulent misrepresentation. 10. Removal of Legends, Etc. Notwithstanding the foregoing provisions of Sections 2 through 9 hereof, the restrictions imposed by Sections 2 through 9 on the transferability of any Preferred Shares, Conversion Shares, Warrant Shares and Perkin-Elmer Shares shall cease and terminate when (a) any such Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares are sold or otherwise disposed of in accordance with the intended method of disposition by the seller or sellers thereof set forth in a registration statement or such other method contemplated by Section 3 hereof that does not require that the securities transferred bear the legend set forth in Section 2 hereof, or (b) the holder of such Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares has met the requirements for transfer pursuant to subparagraph (k) of Rule 144 (as amended from time to time) promulgated by the Commission under the Securities Act. Whenever the restrictions imposed by Sections 2 through 9 hereof have terminated, a holder of a certificate for such Preferred Shares, Perkin-Elmer Shares, Conversion Shares or Warrant Shares as to which such restrictions have terminated shall be entitled to receive from the Company, without expense, a new certificate not bearing the restrictive legend set forth in Section 2 hereof and not containing any other reference to the restrictions imposed by this Agreement. 12 11. Changes in Common Stock or Preferred Stock. If, and as often as, there is any change in the Common Stock or the Preferred Stock by way of a stock split, stock dividend, combination or reclassification, or through a merger, consolidation, reorganization or recapitalization, or by any other means, appropriate adjustment shall be made in the provisions hereof so that the rights and privileges granted hereby shall continue with respect to the Common Stock or the Preferred Stock as so changed. 12. Rule 144 Reporting. With a view to making available the benefits of certain rules and regulations of the Commission which may at any time permit the sale of the Restricted Stock to the public without registration, at all times the Company agrees to: (a) make and keep public information available, as those terms are understood and defined in Rule 144 under the Securities Act; (b) use all reasonable efforts to file with the Commission in a timely manner all reports and other documents required of the Company under the Securities Act and the Exchange Act; and (c) furnish to each holder of Restricted Stock forthwith upon request a written statement by the Company as to its compliance with the reporting requirements of such Rule 144 and of the Securities Act and the Exchange Act, a copy of the most recent annual or quarterly report of the Company, and such other reports and documents so filed by the Company as such holder may reasonably request in availing itself of any rule or regulation of the Commission allowing such holder to sell any Restricted Stock without registration. 13. Representations and Warranties of the Company. The Company represents and warrants to each of the Original Holders as follows: (a) The execution, delivery and performance of this Agreement by the Company have been duly authorized by all requisite corporate action and will not violate any provision of law, any order of any court or other agency of government, the Charter or By-laws of the Company or its subsidiaries or any provision of any indenture, agreement or other instrument to which it or its subsidiaries or any or their properties or assets is bound, or conflict with, result in a breach of or constitute (with due notice or lapse of time or both) a default under any such indenture, agreement or other instrument or result in the creation or imposition of any lien, charge or encumbrance of any 13 nature whatsoever upon any of the properties or assets of the Company or its subsidiaries. (b) This Agreement has been duly executed and delivered by the Company and constitutes the legal, valid and binding obligation of the Company, enforceable in accordance with its terms. 14. Miscellaneous. (a) All covenants and agreements contained in this Agreement by or on behalf of any of the parties hereto shall bind and inure to the benefit of the respective successors and assigns of the parties hereto (including without limitation transferees of any Preferred Shares or Restricted Stock), whether so expressed or not, provided, however, that registration rights conferred herein on the holders of Preferred Shares, Perkin-Elmer Shares, Warrants, or Restricted Stock, shall only inure to the benefit of a transferee of Preferred Shares, Perkin-Elmer Shares, Warrants, or Restricted Stock, if (i) there is transferred to such transferee at least 20% of the total shares of Restricted Stock originally issued pursuant to the Merger Agreement to the direct or indirect transferor of such transferee or (ii) such transferee is a partner, shareholder or affiliate of a party hereto. (b) All notices, requests, consents and other communications hereunder shall be in writing and shall be mailed by certified or registered mail, return receipt requested, postage prepaid, or telexed, in the case of non-U.S. residents, addressed as follows: if to the Company, at: Strategic Diagnostics Inc. 128 Sandy Drive Newark, DE 19713-1147 Attn: President if to any Original Holder, at the most recent address given by such party to the Company; if to any subsequent holder of Preferred Shares, Perkin-Elmer Shares, Warrants, or Restricted Stock, to it at such address as may have been furnished to the Company in writing by such holder; or, in any case, at such other address or addresses as shall have been furnished in writing to the Company (in the case of a holder of Preferred Shares, Perkin-Elmer Shares or Restricted Stock) or 14 to the holders of Preferred Shares, Perkin-Elmer Shares or Restricted Stock (in the case of the Company) in accordance with the provisions of this paragraph. (c) This Agreement shall be governed by and construed in accordance with the laws of the State of Delaware. (d) This Agreement may not be amended or modified, and no provision hereof may be waived, without the written consent of the Company and the holders of at least two-thirds of the outstanding shares of Restricted Stock. In addition, the Agreement may not be amended in a manner that is materially adverse to the rights of the parties hereunder without the written consent of the holders of at least a majority of the outstanding shares of Restricted Stock. (e) This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. (f) The obligations of the Company to register shares of Restricted Stock under Sections 4 or 5 shall terminate on the fifth anniversary of the date of this Agreement. (g) Notwithstanding the provisions of Section 6(a), the Company's obligation to file a registration statement, or cause such registration statement to become and remain effective, shall be suspended for a period not to exceed 90 days in any 12-month period if there exists at the time material non-public information relating to the Company which, in the reasonable opinion of the Company, should not be disclosed. (h) From the date of this Agreement, the Company shall not grant to any third party any registration rights more favorable than any of those contained herein, so long as any of the registration rights under this Agreement remains in effect. (i) If any provision of this Agreement shall be held to be illegal, invalid or unenforceable, such illegality, invalidity or unenforceability shall attach only to such provision and shall not in any manner affect or render illegal, invalid or unenforceable any other provision of this Agreement, and this Agreement shall be carried out as if any such illegal, invalid or unenforceable provision were not contained herein. [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK] 15 Please indicate your acceptance of the foregoing by signing and returning the enclosed counterpart of this letter, whereupon this Agreement shall be a binding agreement between the Company and you. Very truly yours, ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/Grover C. Wrenn ----------------------------- Title: President and Chief Executive Officer AGREED TO AND ACCEPTED as of the date first above written. DSV PARTNERS IV By: DSV Management, Ltd., its general partner By: /s/Mort Collins ---------------------------- General Partner EDISON VENTURE FUND II, L.P. By: Edison Partners II, L.P., General Partner By: /s/Richard J. Defieux ---------------------------- General Partner EDISON VENTURE FUND II-PA, L.P. By: Edison Partners II, L.P., General Partner By: /s/Richard J. Defieux ---------------------------- General Partner THE PERKIN-ELMER CORPORATION By: /s/Stephen O. Jaeger ---------------------------- EX-3 4 EXHIBIT 3 EXHIBIT 3 COMMON STOCK WARRANT NO. W-12/30/96-A THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on June 23, 1993. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 58,635 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X = Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 2 7. Expiration Date. This Warrant shall expire at the close of business on June 23, 1998, and shall be void thereafter. 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 3 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 12. Notices of Record Date, Etc. In the event of: (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the 4 Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ----------------------------------------- Title: President and Chief Executive Officer 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature ________________________________ Name for Registration_____________________ Mailing Address___________________________ __________________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature_________________________________ Name for Registration_____________________ Mailing Address___________________________ __________________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-B THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on October 27, 1994. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 22,337 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; provided, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X = Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on October 27, 1999, and shall be void thereafter. 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by 2 the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 12. Notices of Record Date, Etc. In the event of: (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any 3 dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or 4 (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ________________________________________ Title: President and Chief Executive Officer _____________________________________ 6 SUBSCRIPTION To: ______________________________ Date: ________________________ The undersigned hereby subscribes for _______________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 7 NET ISSUE ELECTION NOTICE To: ______________________________ Date: ________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-C THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on January 2, 1995. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 11,169 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X=Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on January 2, 2000, and shall be void thereafter. 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times 2 from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 12. Notices of Record Date, Etc. In the event of: 3 (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. 4 C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ---------------------------------------- Title: President and Chief Executive Officer ------------------------------------- 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-D THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on April 3, 1995. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 11,169 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X=Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on April 3, 2000, and shall be void thereafter. 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times 2 from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 12. Notices of Record Date, Etc. In the event of: 3 (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. 4 C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ---------------------------------------- Title: President and Chief Executive Officer ------------------------------------- 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature __________________________________ Name for Registration ______________________ Mailing Address ____________________________ ____________________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature __________________________________ Name for Registration ______________________ Mailing Address ____________________________ ____________________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-E THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on April 18, 1995. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 55,843 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X=Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on April 18, 2000, and shall be void thereafter. 2 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 3 12. Notices of Record Date, Etc. In the event of: (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. 4 C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ---------------------------------------- Title: President and Chief Executive Officer ------------------------------------- 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-F THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on July 3, 1995. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 27,922 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X=Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on July 3, 2000, and shall be void thereafter. 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times 2 from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 12. Notices of Record Date, Etc. In the event of: 3 (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. 4 C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ---------------------------------------- Title: President and Chief Executive Officer ------------------------------------- 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature __________________________________ Name for Registration ______________________ Mailing Address ____________________________ ____________________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature __________________________________ Name for Registration ______________________ Mailing Address ____________________________ ____________________________________________ 8 COMMON STOCK WARRANT NO. W-12/30/96-G THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS AVAILABLE WITH RESPECT THERETO. ENSYS ENVIRONMENTAL PRODUCTS, INC. WARRANT TO PURCHASE COMMON STOCK 1. Issuance. This Warrant is issued to DSV Partners IV, L.P., by EnSys Environmental Products, Inc., a Delaware corporation (referred to hereinafter, with its successors, as the "Company"), on this 30th day of December, 1996 (the "Warrant Issuance Date"), in consideration of the surrender to the Company for cancellation of certain warrants to purchase common stock of Strategic Diagnostics Inc., which warrants were issued on August 1, 1995. 2. Purchase Price; Number of Shares. Subject to the terms and conditions hereinafter set forth, the registered holder of this Warrant (the "Holder") is entitled upon surrender of this Warrant with the subscription form annexed hereto, duly executed, at the office of the Company, to purchase 27,922 shares of common stock of the Company, par value $.01 per share (the "Common Stock"), at the per share exercise price of $2.24 (the "Purchase Price"). 3. Payment of Purchase Price. The Purchase Price may be paid (i) in cash or by check, (ii) by the surrender by the Holder to the Company of any promissory notes or other obligations issued by the Company, with all such notes and obligations so surrendered being credited against the Purchase Price in an amount equal to the principal amount thereof plus accrued interest to the date of surrender, (iii) through delivery by the Holder to the Company of other securities issued by the Company, with such securities being credited against the Purchase Price in an amount equal to the fair market value thereof, as determined in good faith by the Board of Directors of the Company (the "Board"), or (iv) by any combination of the foregoing. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of any securities the Holder may wish to deliver to the Company pursuant to clause (iii) above. 4. Net Issue Election. The Holder may elect to receive, without the payment by the Holder of any additional consideration, shares equal to the value of this Warrant or any portion hereof by the surrender of this Warrant or such portion to the Company, with the net issue election notice annexed hereto duly executed, at the office of the Company; PROVIDED, that the Holder may not make such an election unless (i) the Company has registered its securities pursuant to the Securities Act of 1933, as amended, (the "Act") or in connection with such registration or (ii) upon the expiration of this Warrant. Thereupon, the Company shall issue to the Holder such number of fully paid and nonassessable shares of Common Stock as is computed using the following formula: X=Y(A-B) ------ A where X = the number of shares to be issued to the Holder pursuant to this Section 4. Y = the number of shares covered by this Warrant in respect of which the net issue election is made pursuant to this Section 4. A = the fair market value of one share of Common Stock. If the Company's securities are registered pursuant to the Act, the fair market value shall mean the average high and low prices of the Common Stock on the day prior to the exercise of this Warrant, if the Common Stock is being traded on a national exchange; or the last reported sale price on the day prior to exercise of this Warrant, if the Common Stock is traded on the Nasdaq National Market, and if the Common Stock is not traded on a national exchange; or the closing bid price (or average of bid prices) last quoted on the day prior to the exercise of this Warrant by an established quotation service for over-the-counter securities, if the Common Stock is not reported on the Nasdaq National Market or a national exchange. If the election occurs in connection with the registration of securities, then the fair market value shall be the price offered to the public. Otherwise, the fair market value shall be as determined in good faith by the Board, at the time the net issue election is made pursuant to this Section 4. B = the Purchase Price in effect under this Warrant at the time the net issue election is made pursuant to this Section 4. The Board shall promptly respond in writing to an inquiry by the Holder as to the fair market value of one share of Common Stock. 5. Partial Exercise. This Warrant may be exercised in part, and the Holder shall be entitled to receive a new warrant, which shall be dated as of the date of this Warrant, covering the number of shares in respect of which this Warrant shall not have been exercised. 6. Issuance Date. The person or persons in whose name or names any certificate representing shares of Common Stock is issued hereunder shall be deemed to have become the holder of record of the shares represented thereby as at the close of business on the date this Warrant is exercised with respect to such shares, whether or not the transfer books of the Company shall be closed. 7. Expiration Date. This Warrant shall expire at the close of business on August 1, 2000, and shall be void thereafter. 2 8. Reserved Shares; Valid Issuance. The Company covenants that it will at all times from and after the date hereof reserve and keep available such number of its authorized shares of Common Stock, free from all preemptive or similar rights therein, as will be sufficient to permit the exercise of this Warrant in full. The Company further covenants that, assuming the receipt by the Company of the consideration therefor, such shares as may be issued pursuant to the exercise of this Warrant will, upon issuance, be duly and validly issued, fully paid and nonassessable and free from all taxes, liens and charges with respect to the issuance thereof. 9. Dividends. If at any time after the Warrant Issuance Date, the Company subdivides the Common Stock, by split-up or otherwise, or combines the Common Stock, or issues additional shares of Common Stock in payment of a stock dividend on the Common Stock, the number of shares issuable on the exercise of this Warrant shall forthwith be proportionately increased in the case of a subdivision or stock dividend, or proportionately decreased in the case of a combination, and the Purchase Price shall forthwith be proportionately decreased in the case of a subdivision or stock dividend, or proportionately increased in the case of a combination. Whenever the Purchase Price is adjusted, as herein provided, the Company shall promptly deliver to the Holder a certificate of an officer of the Company setting forth the Purchase Price after such adjustment and setting forth a brief statement on the facts requiring such adjustment. 10. Mergers and Reclassifications. If at any time after the Warrant Issuance Date there shall be any reclassification, capital reorganization or change of the Common Stock (other than as a result of a subdivision, combination or stock dividend provided for in Section 9 hereof), or any consolidation of the Company with, or merger of the Company into, another corporation or other business organization (other than a consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change of the outstanding Common Stock), or any sale or conveyance to another corporation or other business organization of all or substantially all of the assets of the Company, then, as a condition of such reclassification, reorganization, change, consolidation, merger, sale or conveyance, lawful provisions shall be made, and duly executed documents evidencing the same from the Company or its successor shall be delivered to the Holder, so that the Holder shall thereafter have the right to purchase, at a total price not to exceed that payable upon the exercise of this Warrant in full, the kind and amount of shares of stock and other securities and property receivable upon such reclassification, reorganization, change, consolidation, merger, sale or conveyance by a holder of the number of shares of Common Stock which might have been purchased by the Holder immediately prior to such reclassification, reorganization, change, consolidation, merger, sale or conveyance, and in any such case appropriate provisions shall be made with respect to the rights and interest of the Holder to the end that the provisions hereof (including without limitation, provisions for the adjustment of the Purchase Price and the number of shares issuable hereunder) shall thereafter be applicable in relation to any shares of stock or other securities and property thereafter deliverable upon exercise hereof. 11. Fractional Shares. In no event shall any fractional share of Common Stock be issued upon any exercise of this Warrant. 3 12. Notices of Record Date, Etc. In the event of: (a) any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, or any right to subscribe for, purchase or otherwise acquire any shares of stock of any class or any other securities or property, or to receive any other right, (b) any reclassification of the capital stock of the Company, capital reorganization of the Company, consolidation or merger involving the Company, or sale or conveyance of all or substantially all of its assets, or (c) any voluntary or involuntary dissolution, liquidation or winding-up of the Company, then and in each such event the Company will mail or cause to be mailed to the Holder a notice specifying (i) the date on which any such record is to be taken for the purpose of such dividend, distribution or right, and stating the amount and character of such dividend, distribution or right, or (ii) the date on which any such reclassification, reorganization, consolidation, merger, sale or conveyance, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record in respect of such event are to be determined. Such notice shall be mailed at least 20 days prior to the date specified in such notice on which any such action is to be taken. 13. Amendment. The terms of this Warrant may be amended, modified or waived only by written agreement of the Company and the Holder. 14. Warrant Register Transfer, Etc. A. The Company will maintain a register containing the names and addresses of the registered holders of outstanding Warrants. The Holder may change its address as shown on the warrant register by written notice to the Company requesting such change. Any notice or written communication required or permitted to be given to the Holder may be given by certified mail or delivered to the Holder at its address as shown on the warrant register. B. This Warrant may not be transferred or assigned in whole or in part by the Holder without the prior written consent of the Company, which consent shall not be unreasonably withheld (it being understood that the Company may withhold consent to any transfer of the Warrant to any person seeking to obtain control of the Company), except that prior written consent of the Company will not be required for a transfer of the Warrant in whole by the Holder to an "affiliate" of the Holder. An "affiliate" of the Holder shall mean any other person or entity directly or indirectly controlling, controlled by or under direct or indirect common control with the Holder. Prior to and as a condition to effecting any such transfer the Holder shall deliver to the Company an opinion of counsel reasonably satisfactory to the Company to the effect that such transfer will comply with all applicable securities laws. 4 C. In case this Warrant shall be mutilated, lost, stolen or destroyed, the Company shall issue a new warrant of like tenor and denomination and deliver the same (i) in exchange and substitution for and upon surrender and cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost, stolen or destroyed, upon receipt of evidence reasonably satisfactory to the Company of the loss, theft or destruction of such Warrant (including a reasonably detailed affidavit with respect to the circumstances of any loss, theft or destruction) and of indemnity reasonably satisfactory to the Company. 15. No Impairment. The Company will not, by amendment of its Certificate of Incorporation or through any reclassification, capital reorganization, consolidation, merger, sale or conveyance of assets, dissolution, liquidation, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Holder. 16. Governing Law. The provisions and terms of this Warrant shall be governed by and construed in accordance with the internal laws of the State of Delaware. 17. Successors and Assigns. This Warrant shall be binding upon the Company's successors and assigns and shall inure to the benefit of the Holder's successors, legal representatives and permitted assigns. 18. Business Days. If the last or appointed day for the taking of any action required or the expiration of any right granted herein shall be a Saturday or Sunday or a legal holiday in Delaware, then such action may be taken or right may be exercised on the next succeeding day which is not a Saturday or Sunday or such a legal holiday. 5 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer, under seal, as of the date above written. ENSYS ENVIRONMENTAL PRODUCTS, INC. By: /s/ Grover C. Wrenn ---------------------------------------- Title: President and Chief Executive Officer ------------------------------------- 6 SUBSCRIPTION To:___________________________ Date:____________________________ The undersigned hereby subscribes for _________________ shares of Common Stock covered by this Warrant. The certificate(s) for such shares shall be issued in the name of the undersigned or as otherwise indicated below: Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 7 NET ISSUE ELECTION NOTICE To:____________________________ Date:________________________ The undersigned hereby elects under Section 4 to surrender the right to purchase ___________ shares of Common Stock Pursuant to this Warrant. The certificate(s) for the shares issuable upon such net issue election shall be issued in the name of the undersigned or as otherwise indicated below. Signature _____________________________ Name for Registration _________________ Mailing Address _______________________ _______________________________________ 8 EX-4 5 EXHIBIT 4 EXHIBIT 4 FOURTH AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF STRATEGIC DIAGNOSTICS INC. ARTICLE I. NAME The name of the Corporation is Strategic Diagnostics Inc. ARTICLE II. REGISTERED OFFICE The address of the registered office of the Corporation in the State of Delaware is Corporation Trust Center, 1209 Orange Street, in the City of Wilmington, County of New Castle. The name of the registered agent of the Corporation at such address is The Corporation Trust Company. . ARTICLE III. PURPOSES The nature of the business or purposes to be conducted or promoted by the Corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of Delaware. ARTICLE IV. CAPITAL STOCK The total number of shares of all classes of capital stock which the Corporation shall have the authority to issue is 54,664,362 shares, divided into classes as follows: 2,164,362 shares shall be shares of Series A Convertible Preferred Stock, with a par value of $.01 per share (the "Series A Convertible Preferred Stock"); 17,500,000 shares shall be shares of Preferred Stock, with a par value of $.01 per share (the "Blank Check Preferred Stock"); and 35,000,000 shares shall be shares of Common Stock, with a par value of $.01 per share (the "Common Stock"); The following is a statement of the powers, preferences, rights, qualifications, limitations and restrictions of the Series A Convertible Preferred Stock, the Blank Check Preferred Stock and the Common Stock: PART A. Series A Convertible Preferred Stock 1. Number of Shares. The series of Preferred Stock designated and known as "Series A Convertible Preferred Stock" shall consist of 2,164,362 shares. 2. Voting. Except as otherwise may be provided in these terms of the Series A Convertible Preferred Stock or by law, the Series A Convertible Preferred Stock and all other classes and series of stock of the Corporation otherwise entitled to vote shall vote together as a single class on all actions to be taken by the stockholders of the Corporation. Each share of Series A Convertible Preferred Stock shall entitle the holder thereof to such number of votes per share on each such action as shall equal the nearest whole number of shares of Common Stock into which each share of Series A Convertible Preferred Stock is then convertible. 3. Dividends. The holders of the Series A Convertible Preferred Stock shall be entitled to receive, out of funds legally available therefor, when and if declared by the Board of Directors, any dividend on or with respect to Common Stock (other than a dividend payable solely in shares of Common Stock) in an amount equal to the product obtained by multiplying the dividend declared or payable on each share of Common Stock times the nearest whole number of shares of Common Stock into which each share of Series A Convertible Preferred Stock is then convertible. 4. Liquidation. Upon any liquidation, dissolution or winding up of the Corporation (other than in connection with a reorganization of the Corporation in which the rights and preferences of the Series A Convertible Preferred Stock are not adversely affected), whether voluntary or involuntary, the holders of Series A Convertible Preferred Stock shall be entitled, before any distribution or payment is made upon any stock ranking on liquidation junior to the Series A Convertible Preferred Stock, to be paid an amount equal to $2.9466849 per share of Series A Convertible Preferred Stock up to an aggregate maximum of $6,377,693 (in the aggregate, the "Liquidation Preference") (such amount payable with respect to one share of Series A Convertible Preferred Stock sometimes shall be referred to as the "Liquidation Payment"); provided, however, that the Liquidation Preference shall be automatically reduced in an aggregate amount equal to any dividends paid to the holders of Series A Convertible Preferred Stock and the Liquidation Payment shall be reduced on a per share basis for such payment of dividends. If upon such liquidation, dissolution or winding up of the Corporation, whether 2 voluntary or involuntary, the assets to be distributed among the holders of Series A Convertible Preferred Stock shall be insufficient to permit payment to the holders of the Series A Convertible Preferred Stock of the full Liquidation Preference, then the entire assets of the Corporation legally available for distribution shall be distributed ratably among the holders of Series A Convertible Preferred Stock. Upon any such liquidation, dissolution or winding up of the Corporation, after the holders of Series A Convertible Preferred Stock shall have been paid the full Liquidation Preference, the remaining net assets of the Corporation may be distributed to the holders of stock ranking on liquidation junior to the Series A Convertible Preferred Stock. Written notice of such liquidation, dissolution or winding up, stating a payment date, the amount of the Liquidation Payment and the place where said Liquidation Payment shall be payable, shall be given by mail, postage prepaid, or by telex to non-U.S. residents, not less than 20 days prior to the payment date stated therein, to the holders of record of Series A Convertible Preferred Stock, such notice to be addressed to each such holder at its address as shown by the records of the Corporation. 5. Restrictions. At any time when shares of Series A Convertible Preferred Stock are outstanding, except where the vote or written consent of the holders of a greater number of shares of the Corporation is required by law or by the Certificate of Incorporation, and in addition to any other vote required by law or the Certificate of Incorporation, without the approval of the holders of at least two-thirds of the then outstanding shares of Series A Convertible Preferred Stock, given in writing or by vote at a meeting, consenting or voting (as the case may be) separately as a series, the Corporation will not: 5A. Create or authorize the creation of any additional class or series of shares of stock unless the same ranks junior to the Series A Convertible Preferred Stock as to the distribution of assets on the liquidation, dissolution or winding up of the Corporation, or increase the authorized amount of the Series A Convertible Preferred Stock or increase the authorized amount of any additional class or series of shares of stock unless the same ranks junior to the Series A Convertible Preferred Stock as to the distribution of assets on the liquidation, dissolution or winding up of the Corporation, or create or authorize any obligation or security convertible into shares of Series A Convertible Preferred Stock or into shares of any other class or series of stock unless the same ranks junior to the Series A Convertible Preferred Stock as to the distribution of assets on the liquidation, dissolution or winding up of the Corporation; or 5B. Redeem or otherwise acquire any shares of Series A Convertible Preferred Stock, except as expressly authorized in paragraph 7 hereof or pursuant to a purchase offer made pro rata to all holders of the shares of Series A Convertible Preferred Stock on the basis of the aggregate number of outstanding shares of Series A Convertible Preferred Stock then held by each such holder. 6. Conversions. The holders of shares of Series A Convertible Preferred Stock shall have the following conversion rights: 3 6A. Right to Convert. Subject to the terms and conditions of this paragraph 6, the holder of any share or shares of Series A Convertible Preferred Stock shall have the right, at its option at any time, to convert any such shares of Series A Convertible Preferred Stock (except that upon any liquidation of the Corporation the right of conversion shall terminate at the close of business on the business day fixed for payment of the Liquidation Payment) into an equal number of fully paid and nonassessable shares of Common Stock, subject to adjustment as provided in subparagraphs 6D and 6E. Such rights of conversion shall be exercised by the holder thereof by giving written notice that the holder elects to convert a stated number of shares of Series A Convertible Preferred Stock into Common Stock and by surrender of a certificate or certificates for the shares so to be converted to the Corporation at its principal office (or such other office or agency of the Corporation as the Corporation may designate by notice in writing to the holders of the Series A Convertible Preferred Stock) at any time during its usual business hours on the date set forth in such notice, together with a statement of the name or names (with address) in which the certificate or certificates for shares of Common Stock shall be issued. 6B. Issuance of Certificates; Time Conversion Effected. Promptly after the receipt of the written notice referred to in subparagraph 6A and surrender of the certificate or certificates for the share or shares of Series A Convertible Preferred Stock to be converted, the Corporation shall issue and deliver, or cause to be issued and delivered, to the holder, registered in such name or names as such holder may direct, a certificate or certificates for the number of whole shares of Common Stock issuable upon the conversion of such share or shares of Series A Convertible Preferred Stock. To the extent permitted by law, such conversion shall be deemed to have been effected as of the close of business on the date on which such written notice shall have been received by the Corporation and the certificate or certificates for such share or shares shall have been surrendered as aforesaid, and at such time the rights of the holder of such share or shares of Series A Convertible Preferred Stock shall cease, and the person or persons in whose name or names any certificate or certificates for shares of Common Stock shall be issuable upon such conversion shall be deemed to have become the holder or holders of record of the shares represented thereby. 6C. Fractional Shares; Dividends; Partial Conversion. No fractional shares shall be issued upon conversion of Series A Convertible Preferred Stock into Common Stock and no payment or adjustment shall be made upon any conversion on account of any cash dividends on the Common Stock issued upon such conversion. At the time of each conversion, the Corporation shall pay in cash an amount equal to all dividends accrued and unpaid on the shares of Series A Convertible Preferred Stock surrendered for conversion to the date upon which such conversion is deemed to take place as provided in subparagraph 6B. In case the number of shares of Series A Convertible Preferred Stock represented by the certificate or certificates surrendered pursuant to subparagraph 6A exceeds the number of shares converted, the Corporation shall, upon such conversion, execute and deliver to the holder, at the expense of the Corporation, a new certificate or certificates for the number of shares of Series A Convertible Preferred Stock represented by the certificate or certificates surrendered which are not to be converted. If any fractional share of Common Stock would, except for the provisions of the first sentence of this subparagraph 6C, be delivered upon such conversion, the Corporation, in lieu of 4 delivering such fractional share, shall pay to the holder surrendering the Series A Convertible Preferred Stock for conversion an amount in cash equal to the current market price of such fractional share as determined in good faith by the Board of Directors of the Corporation. 6D. Subdivision or Combination of Common Stock. In case the Corporation shall at any time subdivide (by any stock split, stock dividend or otherwise) its outstanding shares of Common Stock into a greater number of shares, the number of shares of Common Stock issuable upon conversion of each share of Series A Convertible Preferred Stock shall be increased in proportion to such increase in outstanding shares, and, conversely, in case the outstanding shares of Common Stock shall be combined into a smaller number of shares, the number of shares of Common Stock issuable upon conversion of each share of Series A Convertible Preferred Stock shall be decreased in proportion to such decrease in outstanding shares. 6E. Reorganization or Reclassification. If any capital reorganization or reclassification of the capital stock of the Corporation shall be effected in such a way that holders of Common Stock shall be entitled to receive stock, securities or assets with respect to or in exchange for Common Stock, then, as a condition of such reorganization or reclassification, lawful and adequate provisions shall be made whereby each holder of a share or shares of Series A Convertible Preferred Stock shall thereupon have the right to receive, upon the basis and upon the terms and conditions specified herein and in lieu of the shares of Common Stock immediately theretofore receivable upon the conversion of such share or shares of Series A Convertible Preferred Stock, such shares of stock, securities or assets as may be issued or payable with respect to or in exchange for a number of outstanding shares of such Common Stock equal to the number of shares of such Common Stock immediately theretofore receivable upon such conversion had such reorganization or reclassification not taken place, and in any such case appropriate provisions shall be made with respect to the rights and interests of such holder to the end that the provisions hereof shall thereafter be applicable, as nearly as may be, in relation to any shares of stock, securities or assets thereafter deliverable upon the exercise of such conversion rights. 6F. Certain Notices. In case at any time: (1) the Corporation shall declare any dividend upon its Common Stock payable in cash or stock or make any other distribution to the holders of its Common Stock; (2) the Corporation shall offer for subscription pro rata to the holders of its Common Stock any additional shares of stock of any class or other rights; (3) there shall be any capital reorganization or reclassification of the capital stock of the Corporation, or a consolidation or merger of the Corporation with or into, or a sale of all or substantially all its assets to, another entity or entities; or 5 (4) there shall be a voluntary or involuntary dissolution, liquidation or winding up of the Corporation; then, in any one or more of said cases, the Corporation shall give, by first class mail, postage prepaid, or by telex to non U.S. residents, addressed to each holder of any shares of Series A Convertible Preferred Stock at the address of such holder as shown on the books of the corporation, (a) at least 20 days' prior written notice of the date on which the books of the Corporation shall close or a record shall be taken for such dividend, distribution or subscription rights or for determining rights to vote in respect of any such reorganization, reclassification, consolidation, merger, sale, dissolution, liquidation or winding up and (b) in the case of any such reorganization, reclassification, consolidation, merger, sale, dissolution, liquidation or winding up, at least 20 days' prior written notice of the date when the same shall take place. Such notice in accordance with the foregoing clause (a) shall also specify, in the case of any such dividend, distribution or subscription rights, the date on which the holders of Common Stock shall be entitled thereto and such notice in accordance with the foregoing clause (b) shall also specify the date on which the holders of Common Stock shall be entitled to exchange their Common Stock for securities or other property deliverable upon such reorganization, reclassification, consolidation, merger, sale, dissolution, liquidation or winding up, as the case may be. 6G. Stock to be Reserved. The Corporation will at all times reserve and keep available out of its authorized Common Stock, solely for the purpose of issuance upon the conversion of Series A Convertible Preferred Stock as herein provided, such number of shares of Common Stock as shall then be issuable upon the conversion of all outstanding shares of Series A Convertible Preferred Stock. The Corporation covenants that, assuming the receipt by the Corporation of the consideration therefor, all shares of Common Stock which shall be so issued shall be duly and validly issued and fully paid and nonassessable. 6H. No Reissuance of Series A Convertible Preferred Stock. Shares of Series A Convertible Preferred Stock which are converted into shares of Common Stock as provided herein shall be canceled and shall not be reissued. 6I. Closing of Books. The Corporation will at no time close its transfer books against the transfer of any Series A Convertible Preferred Stock or of any shares of Common Stock issued or issuable upon the conversion of any shares of Series A Convertible Preferred Stock in any manner which interferes with the timely conversion of such Series A Convertible Preferred Stock, except as may otherwise be required to comply with applicable securities laws. 6J. Mandatory Conversion. If the closing share price of Common Stock listed on the NASDAQ National Market System equals or exceeds $4.50 per share for a period of forty-five (45) consecutive business days, all outstanding shares of Series A Convertible Preferred Stock shall automatically convert to shares of Common Stock. 6 7. Redemption. The shares of Series A Convertible Preferred Stock shall be redeemed as follows: 7A. Redemption at Holders' Option. In the event the Corporation enters into a merger, consolidation, recapitalization, reorganization or any other transaction pursuant to which the Series A Convertible Preferred Stock would be converted into or exchanged for: (i) preferred stock with lesser rights or a lesser Liquidation Preference; or (ii) for common stock that in the aggregate has a lesser aggregate fair market value than the Liquidation Preference; or (iii) for an aggregate amount of cash that is less than the Liquidation Preference; then on the written request (the "Holder Redemption Request") of the holders of at least 66 2/3% of the outstanding shares of Series A Convertible Preferred Stock, then at or before the closing of such transaction, the Corporation shall redeem from each holder of shares of Series A Convertible Preferred Stock all of the shares of Series A Convertible Preferred Stock held by such holder for an aggregate amount equal to the Liquidation Preference. 7B. Redemption at Corporation's Option. Upon at least sixty (60) days' prior written notice, the Corporation may redeem effective at any time on or after June 23, 2001, from each holder of shares of Series A Convertible Preferred Stock all of the shares of Series A Convertible Preferred Stock held by such holder. 7C. Redemption Price and Payment. The Series A Convertible Preferred Stock to be redeemed pursuant to Subparagraph 7B shall be redeemed by paying for each share in cash an amount equal to the Liquidation Payment, such amount also being referred to as the "Redemption Price". Such payment shall be made in full to the holders entitled thereto. 7D. Redemption Mechanics. At least 20 but not more than 30 days prior to the date of any redemption (the "Redemption Date"), written notice (the "Redemption Notice") shall be given by the Corporation by mail, postage prepaid, or by telex to non-U.S. residents for which telex instructions shall have been provided to the Corporation for such purpose, to each holder of record (at the close of business on the business day next preceding the day on which the Redemption Notice is given) of shares of Series A Convertible Preferred Stock notifying such holder of the redemption and specifying the Redemption Price, the Redemption Date and the place where said Redemption Price shall be payable. The holders of at least 66-2/3% of the Series A Convertible Preferred Stock may rescind any Holder Redemption Request at any time prior to the close of business on the 10th day after receipt of the Redemption Notice by giving written notice of rescission to the Corporation; provided, that the holders of Series A Convertible Preferred Stock may not thereafter submit a subsequent Holder Redemption Request in respect of the same transaction. The Redemption Notice shall be addressed to each holder at his address as shown by the records of the Corporation. From and after the close of business on the Redemption Date, unless there shall have been a default in the payment of the Redemption Price, all rights of holders of shares of Series A Convertible Preferred Stock (except the right to receive the Redemption Price) shall cease with respect to such shares, and such shares shall not thereafter be transferred on the books of the Corporation or be deemed to be outstanding for any purpose whatsoever. If the funds of the Corporation legally available for redemption of shares of 7 Series A Convertible Preferred Stock on the Redemption Date are insufficient to redeem the total number of outstanding shares of Series A Convertible Preferred Stock, the holders of shares of Series A Convertible Preferred Stock shall share ratably in any funds legally available for redemption of such shares according to the respective amounts which would be payable with respect to the full number of shares owned by them if all such outstanding shares were redeemed in full. The shares of Series A Convertible Preferred Stock not redeemed shall remain outstanding and entitled to all rights and preferences provided herein. At any time thereafter when additional funds of the Corporation are legally available for the redemption of such shares of Series A Convertible Preferred Stock, such funds will be used, at the end of the next succeeding fiscal quarter, to redeem the balance of such shares, or such portion thereof for which funds are then legally available, on the basis set forth above. 7E. Redeemed or Otherwise Acquired Shares to be Retired. Any shares of Series A Convertible Preferred Stock redeemed pursuant to this paragraph 7 or otherwise acquired by the Corporation in any manner whatsoever shall be canceled and shall not under any circumstances be reissued; and the Corporation may from time to time take such appropriate corporate action as may be necessary to reduce accordingly the number of authorized shares of Series A Convertible Preferred Stock. PART B. Blank Check Preferred Stock 1. Designation and Amount. The designation of this class of capital stock shall be "Blank Check Preferred Stock," par value $.01 per share. Subject to the provisions of this Article IV and the express provisions of each series of Blank Check Preferred Stock, the Board of Directors is hereby empowered to cause the Corporation to issue from time to time, in one or more series, up to 17,500,000 shares of Blank Check Preferred Stock. 2. Rights. The powers, designations, preferences, terms, conditions, privileges and other rights of each series of Blank Check Preferred Stock shall be determined by the Board of Directors in accordance with Section 151 of the Delaware General Corporation Law, subject to the provisions of Part A, Paragraph 5A of this Article IV. Except in respect of the particulars fixed by the Board of Directors for each such series, all Blank Check Preferred Stock shall be of equal rank and identical. PART C. Common Stock 1. Designation and Amount. The designation of this class of capital stock shall be "Common Stock," par value $.01 per share ("Common Stock"). The number of authorized shares of Common Stock may be increased or decreased (but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of the majority of the stock of the Corporation entitled to vote, irrespective of the provisions of Section 242(b)(2) of the Delaware General Corporation Law. 8 2. Voting. Each share of Common Stock shall have one vote upon all matters to be voted on by the holders of Common Stock, which voting rights shall not be cumulative. 3. Other Rights. Each share of Common Stock shall be entitled to participate equally in all dividends payable with respect to the Common Stock and to share ratably, subject to the rights and preferences of the Series A Convertible Preferred Stock and/or any series of the Blank Check Preferred Stock, in all assets of the Corporation in the event of any voluntary or involuntary liquidation, dissolution or winding up of the affairs of the Corporation, or upon any distribution of the assets of the Corporation. ARTICLE V. CERTAIN BUSINESS COMBINATIONS PART A. Vote Required for Certain Business Combinations. 1. Required Vote for Certain Business Combinations. In addition to any affirmative vote required by law or by this Certificate of Incorporation, and except as otherwise expressly provided in Paragraph 2 of this Article V, Part A: 1A. any merger or consolidation of the Corporation or any Subsidiary (as hereinafter defined) with (a) any Interested Stockholder (as hereinafter defined) or (b) any other corporation or entity (whether or not itself an Interested Stockholder) which is, or after such merger or consolidation would be, an Affiliate (as hereinafter defined) of any Interested Stockholder; or 1B. any sale, lease, exchange, mortgage, pledge, transfer or other disposition (in one transaction or a series of transactions) to or with any Interested Stockholder or any Affiliate of any Interested Stockholder of any assets of the Corporation or any Subsidiary having an aggregate Fair Market Value (as hereinafter defined) of $5,000,000 or more; or 1C. the issuance or transfer by the Corporation or any Subsidiary (in one transaction or a series of transactions) of any securities of the Corporation or any Subsidiary to any Interested Stockholder or any Affiliate of any Interested Stockholder in exchange for cash, securities or other property (or a combination thereof) having an aggregate Fair Market Value of $5,000,000 or more; or 1D. the adoption of any plan or proposal for the liquidation, dissolution or winding up of the Corporation proposed by or on behalf of any Interested Stockholder or any Affiliate of any Interested Stockholder; or 1E. any reclassification of securities (including any reverse stock split), or recapitalization of the Corporation, or any merger or consolidation of the Corporation with any of its Subsidiaries or any other transaction (whether or not with or into or otherwise involving any Interested Stockholder) which has the effect, directly or indirectly, of increasing the 9 proportionate share of the outstanding shares of any class of equity or convertible securities of the Corporation or any Subsidiary which is directly or indirectly owned by any Interested Stockholder or any Affiliate of any Interested Stockholder; shall require, subject to Paragraph 2 of this Article V, Part A, the affirmative vote of the holders of at least two-thirds of the voting power of the then outstanding Voting Stock (as hereinafter defined), voting together as a single class at a duly constituted meeting of stockholders called expressly for such purpose. Such affirmative vote shall be required notwithstanding the fact that no vote may be required, or that a lesser percentage may be specified, by law. 2. Definition of "Business Combination. The term "Business Combination" as used in this Article V shall mean any transaction which is referred to in any one or more of Subparagraphs (1A) through (1E) of this Paragraph 1 of Article V, Part A. PART B. When Higher Vote is Not Required. The provisions of Paragraph 1 of this Article V, Part A, shall not be applicable to any particular Business Combination, and such Business Combination shall require only such affirmative vote, if any, as is required by law and any other provision of this Certificate of Incorporation, if all of the conditions specified in either of the following Paragraph 1 or 2 or this Part B are met: 1. Approval by Continuing Directors. The Business Combination shall have been approved by the affirmative vote of a majority of the Continuing Directors (as herein defined) then in office. 2. Price and Procedure Requirements. All of the following conditions shall have been met: 2A. The aggregate amount of the cash and the Fair Market Value, as of the date of the consummation of the Business Combination, of consideration other than cash to be received per share by holders of common stock in such Business Combination shall be at least equal to the highest of the following: (1) (if applicable) the highest per share price (including any brokerage commissions, transfer taxes and soliciting dealers' fees) paid by the Interested Stockholder for any shares of common stock acquired by it (1) within the two-year period immediately prior to and including the first public announcement of the proposal of the Business Combination (the "Announcement Date") or (2) in the transaction in which it became an Interested Stockholder, whichever is higher; and (2) the Fair Market Value per share of common stock on the Announcement Date or on the date on which the Interested Stockholder became an Interested 10 Stockholder (such latter date is referred to in this Article V as the "Determination Date"), whichever is higher. 2B. The aggregate amount of the cash and the Fair Market Value, as of the date of the date of the consummation of the Business Combination, of consideration other than cash to be received per share by holders of shares of any other class of outstanding Voting Stock in such Business Combination shall be at least equal to the highest of the following (it being intended that the requirements of this Subparagraph 2B shall be required to be met with respect to every other class of outstanding Voting Stock, whether or not the Interested Stockholder has previously acquired any shares of a particular class of Voting Stock): (1) (if applicable) the highest per share price (including any brokerage commissions, transfer taxes and soliciting dealers' fees) paid by the Interested Stockholder for any shares of such class of Voting Stock acquired by it (1) within the two-year period immediately prior to and including the Announcement Date or (2) in the transaction in which it became an Interested Stockholder, whichever is higher; (2) (if applicable) the highest preferential amount per share which the holders of shares of such class of Voting Stock are entitled to receive from the Corporation in the event of any voluntary or involuntary liquidation, dissolution or winding up of the Corporation; and (3) the Fair Market Value per share of such class of voting Stock on the Announcement Date or on the Determination Date, whichever is higher. 2C. The consideration to be received by holders of a particular class of outstanding Voting Stock shall be in cash or in the same form as the Interested Stockholder has previously paid for shares of such class of Voting Stock. If the Interested Stockholder has paid for shares of any class of Voting Stock with varying forms of consideration, the form of consideration for such class of Voting Stock shall be either cash or the form used to acquire the largest number of shares of such class of Voting Stock previously acquired by such Interested Stockholder. 2D. After such Interested Stockholder has become an Interested Stockholder and prior to the consummation of such Business Combination: (a) there shall have been (1) no failure to declare and pay at regular dates therefor the full amount of any dividends (whether or not cumulative) payable on any class or series of preferred stock, except as approved by the affirmative vote of a majority of the Continuing Directors; (2) no reduction in the annual rate of dividends paid on the common stock (except as necessary to reflect any subdivision of the common stock), except as approved by the affirmative vote of a majority of the Continuing Directors; and (3) an increase in such annual rate of dividends as necessary to reflect any reclassification (including any reverse stock split), recapitalization, reorganization or any similar transaction which has the effect of reducing the number of outstanding shares of the common stock, unless the failure so to increase such annual rate is approved by the affirmative vote of a 11 majority of the Continuing Directors; and (b) such Interested Stockholder shall not have become the beneficial owner of any additional shares of Voting Stock except as part of the transaction which results in such Interested Stockholder becoming an Interested Stockholder. 2E. After such Interested Stockholder has become an Interested Stockholder, such Interested Stockholder shall not have received the benefit, directly or indirectly (except proportionately as a stockholder), of any loans, advances, guarantees, pledges or other financial assistance or any tax credits or other tax advantages provided by the Corporation, whether in anticipation of or in connection with such Business Combination or otherwise, unless such transaction shall have been approved or ratified by the affirmative vote of a majority of the Continuing Directors after such person shall have become an Interested Stockholder. 2F. A proxy or information statement describing the proposed Business Combination and complying with the requirements of the Securities Exchange Act of 1934 and the rules and regulations thereunder (or any subsequent provisions replacing such Act, rules and regulations) shall be mailed to public stockholders of the Corporation at least 20 days prior to the consummation of such Business Combination (whether or not such proxy or information statement is required to be mailed pursuant to such Act, rules or regulations or subsequent provisions thereof). PART C. Certain Definitions. For the purposes of this Article V: 1. A "person" shall mean an individual, a Group Acting in Concert, a corporation, a partnership, an association, a joint stock company, a trust, a business trust, a government or political subdivision, any unincorporated organization, or any other association or entity. 2. "Interested Stockholder" shall mean any person who or which: 2A. is the beneficial owner, directly or indirectly, of 15% or more of the voting power of the then outstanding shares of Voting Stock; or 2B. is an Affiliate of the Corporation and at any time within the two-year period immediately prior to and including the date in question was the beneficial owner, directly or indirectly, of 15% or more of the voting power of the then outstanding shares of Voting Stock; or 2C. is an assignee of or has otherwise succeeded to the beneficial ownership of any shares of Voting Stock which were at any time within the two-year period immediately prior to and including the date in question beneficially owned by any Interested Stockholder, if such assignment or succession shall have occurred in the course of a transaction or series of transactions not involving a public offering within the meaning of the Securities Act 12 of 1933 (or any subsequent provisions replacing such Act or the rules and regulations promulgated thereunder) and such assignment or succession was not approved by a majority of the Continuing Directors; provided, however, that the term "Interested Stockholder" shall not include (a) the Corporation; (b) any Subsidiary of the Corporation; (c) any person, directly or indirectly, owning of record or beneficially 100% of the issued and outstanding capital stock of the Corporation (other than directors' qualifying shares, if any); (d) any employee benefit plan or compensation arrangement of the Corporation or any Subsidiary of the Corporation; (e) any person holding shares of voting Stock organized, appointed or established by the Corporation or any Subsidiary for or pursuant to the terms of any such employee benefit plan or compensation arrangement; or (f) any Grandfathered Person unless such Grandfathered Person becomes, after the closing of the initial public offering of shares of common stock of the Corporation, the beneficial owner of more than the Grandfathered Percentage of the Voting Stock then outstanding. Any Grandfathered Person who becomes, after the close of business on the date of the closing of the initial public offering of shares of common stock of the Corporation, the beneficial owner of less than 15% of the voting power of the then outstanding shares of Voting Stock shall cease to be a Grandfathered Person. Notwithstanding the foregoing, no person shall become an "Interested Stockholder" as the result of an acquisition of Voting Stock by the Corporation which, by reducing the number of shares outstanding, increases the proportionate number of shares beneficially owned by such person to 15% (or, if applicable, the Grandfathered Percentage with respect to such person) or more of the voting power of the then outstanding shares of Voting Stock; provided, however, that if a person shall become the beneficial owner of 15% (or, if applicable, the Grandfathered Percentage with respect to such person) or more of the voting power of the then outstanding shares of Voting Stock by reason of share purchases by the Corporation and shall, after such share purchases by the Corporation, become the beneficial owner of any additional shares of Voting Stock of the Corporation (other than any shares of Voting Stock issued to such person as a result of a stock dividend, stock split, reclassification, recapitalization, or other similar transaction involving the issuance of shares of Voting Stock on a pro rata basis to all holders of voting Stock), then such person shall be deemed to be an "Interested Stockholder" if immediately thereafter the voting power of the shares of Voting Stock beneficially owned by such person equals or exceeds 15% (or in the case of a Grandfathered Person, the Grandfathered Percentage with respect to such person) or more of the voting power of all of the shares of Voting Stock then outstanding. 3. A person shall be deemed the "beneficial owner" of, and shall be deemed to beneficially own, any Voting Stock: 3A. which such person or any of such person's Affiliates or Associates, directly or indirectly, beneficially owns (as determined pursuant to Rule 13d-3 of the Rules and Regulations promulgated by the Securities and Exchange Commission under the Securities Exchange Act of 1934, as amended (the "1934 Act")); or 13 3B. which such person or any of its Affiliates or Associates, directly or indirectly, has or shares with respect to the Voting Stock (a) the right to acquire, or direct the acquisition of (whether such right is exercisable immediately, or only after the passage of time or upon the satisfaction of any conditions, or both), such Voting Stock pursuant to any agreement, arrangement, understanding or otherwise (whether or not in writing) (other than customary arrangements with and between underwriters and selling group members with respect to a bona fide public offering of securities) or upon the exercise of conversion rights, exchange rights, warrants or options, or otherwise; provided, however, that a person shall not be deemed the "beneficial owner" of, or to "beneficially own," securities tendered pursuant to a tender or exchange offer made by or on behalf of such person or any of such person's Affiliates or Associates until such tendered securities are accepted for purchase or exchange, (b) the right to vote, or to direct the voting of, such Voting Stock pursuant to any agreement, arrangement, understanding or otherwise (whether or not in writing) (provided that a person shall not be deemed to be the beneficial owner of any securities if the agreement, arrangement or understanding to vote such security arises solely from a revocable proxy given in response to a public proxy or consent solicitation made pursuant to, and in accordance with, the Rules and Regulations promulgated under the 1934 Act and is not also then reportable by such person on Schedule 13D under the 1934 Act (or any comparable or successor report)), or (c) the right to dispose of, or to direct the disposition of, such Voting Stock pursuant to any agreement, arrangement, understanding or otherwise (whether or not in writing) (other than customary arrangement with and between underwriters and selling group members with respect to a bona fide public offering of securities ); or 3C. which is beneficially owned, directly or indirectly, by any other person (or any Affiliate or Associate thereof) with which such person or any of such person's Affiliates or Associates has any agreement, arrangement, understanding or otherwise (whether or not in writing) (other than customary arrangements with and between underwriters and selling group members with respect to a bona fide public offering of securities) for the purpose of acquiring, holding, voting (except pursuant to a revocable proxy described in Subparagraph 3B above) or disposing of any shares of Voting Stock. provided, however, that (1) no person engaged in business as an underwriter of securities shall be deemed the beneficial owner of any securities acquired through such person's participation as an underwriter in good faith in a firm commitment underwriting until the expiration of 40 days after the date of such acquisition and (2) no person who is a director or an officer of the Corporation shall be deemed, solely as a result of his or her participation as director or officer of the Corporation, the beneficial owner of any securities of the Corporation that are beneficially owned by any other director or officer of the Corporation. 3D. Notwithstanding anything in the definition of beneficial owner to the contrary, the phrase "then outstanding," when used with reference to a person's beneficial ownership of securities of the Corporation, shall mean the number of such securities then issued and outstanding together with the number of such securities not then actually issued and outstanding which such person would be deemed to own beneficially hereunder. 14 3E. "Affiliate" and "Associate" shall have the respective meanings ascribed to such terms in Rule 12b-2 f the General Rules and Regulations under the 1934 Act (or any subsequent provisions replacing the 1934 Act or the rules and regulations promulgated thereunder); provided, however, that no person who is a director or officer of the Corporation shall be deemed an Affiliate or Associate of any other director or officer of the Corporation solely as a result of his or her position as a director or officer of the Corporation. 3F. "Subsidiary" means any corporation of which a majority of any class of equity security is owned, directly or indirectly, by the Corporation; provided, however, that for the purposes of the definition of Interested Stockholder set forth in Paragraph 2 of this Part C, the term "Subsidiary" shall mean only a corporation of which a majority of each class of equity security is owned, directly or indirectly, by the Corporation. 3G. "Continuing Director" means (i) any member of the Board of Directors of the Corporation who is not an Interested Stockholder of an Affiliate or Associate of an Interested Stockholder and was a member of the Board of Directors prior to the time that the interested Stockholder became an Interested Stockholder, and (ii) any person who subsequently becomes a member of the Corporation's Board of Directors who is not an Associate or Affiliate of an Interested Stockholder and is recommended or approved by the affirmative vote of a majority of the Continuing Directors. 3H. "Fair Market Value" means: (1) in the case of stock, the highest closing sale price during the 30-day period immediately prior to and including the date in question of a share of such stock on the principal United States securities exchange registered under the 1934 Act (or any subsequent provisions replacing such Act or rules or regulations promulgated thereunder) on which such stock is listed, or, if such stock is not listed on any such exchange, the highest closing bid quotation with respect to a share of such stock during the 30-day period immediately prior to and including the date in question on the National Association of Securities Dealers Automated Quotation System or any comparable value system then in use, or if no such quotations are available, the fair market value on the date in question of a share of such stock as determined by the affirmative vote of a majority of the Continuing Directors of the Board of Directors in good faith; and (2) in the case of property other than cash or stock, the fair market value of such property on the date in question is determined by an affirmative vote of a majority of the Continuing Directors of the Board of Directors in good faith. 3I. "Group Acting in Concert" shall mean persons seeking to combine or pool their voting or other interests in the securities of the Corporation for a common purpose, pursuant to any contract, understanding or relationship, agreement or other arrangement, whether written, oral or otherwise, or any "group of persons" as defined under Section 13(d) of the 1934 15 Act (or any subsequent provisions replacing such Act or rules or regulations promulgated thereunder). When persons act together for any such purpose, their group is deemed to have acquired their stock. 3J. In the event of any Business Combination in which the Corporation survives, the phrase "consideration other than cash to be received" as used in this Article V shall include the shares of common stock and/or the shares of any other class of outstanding Voting Stock retained by the holders of such shares. 3K. "Voting Stock" shall mean the outstanding shares of capital stock of the Corporation entitled, at the time, to vote generally in the election of Directors. 3L. "Grandfathered Percentage" shall mean , with respect to any Grandfathered Person, the percentage of the voting power of the then outstanding shares of Voting Stock that such Grandfathered Person beneficially owns as of the close business on the date of the closing of the initial public offering of shares of common stock of the Corporation in the fall of 1993 plus an additional two (2) percentage points; provided, however, that in the event the underwriters exercise their over-allotment option in connection with this initial public offering of shares of common stock, the Grandfathered Percentage shall, from and after the closing of such over-allotment option, mean, with respect to any Grandfathered Person, the percentage of the voting power of the then outstanding shares of Voting Stock that such Grandfathered Person beneficially owns as of the close of business on the date of the closing of the over-allotment option plus an additional two (2) percentage points; and provided, further, that, in the event of any Grandfathered Person shall sell, transfer or otherwise dispose of any outstanding shares of Voting Stock after the close of business on the date of the closing of the initial public offering of the Corporation's common stock in the fall of 1993, the Grandfathered Percentage shall, subsequent to such sale, transfer or disposition, mean, with respect to such Grandfathered Person, the lesser of (i) the Grandfathered Percentage as in effect immediately prior to such sale, transfer, or disposition or (ii) the percentage of the voting power of the then outstanding shares of Voting Stock that such Grandfathered Person beneficially owns immediately following such sale, transfer or disposition plus an additional two (2) percentage points. 3M. "Grandfathered Person" shall mean any Person who or which, together with all Affiliates and Associates of such Person, is, as of the close of business on the date of the closing of the initial public offering of shares of common stock of the Corporation in the fall of 1993, the beneficial owner of 15% or more of the voting power of the then outstanding Voting Stock at such time. 3N. The term "voting power" shall mean, with respect to each outstanding share of capital stock of the Corporation, the number of votes of which a holder of such share shall be entitled, at the time, to vote generally in the election of the Directors. 16 PART D. Powers of the Board of Directors. A majority of the Directors of the Corporation, unless there is an Interested Stockholder, in which case a majority of the Continuing Directors then in office, shall have the power to determine for the purposes of this Article V, on the basis of information known to them after reasonable inquiry, (i) whether a person is an Interested Stockholder, (ii) the number or percentage of shares of Voting Stock or other equity securities beneficially owned by any person, (iii) whether a person is an Affiliate or Associate of, or is affiliated or associated with, another person, (iv) whether the assets which are the subject of any Business Combination have, or the consideration to be received for the issuance or transfer of securities by the Corporation or any Subsidiary in any Business Combination, has, an aggregate Fair Market Value of $5,000,000 or more, (v) whether the requirements of Part B of this Article V have been met with respect to any Business Combination, and (vi) any other matters of interpretation arising under this Article V. The good faith determination by the affirmative vote of a majority of the Directors, or, if there is an Interested Stockholder, by the affirmative vote of a majority of the Continuing Directors then in office, on such matters shall be conclusive and binding for all purposes of this Article V. PART E. No Effect on Fiduciary Obligations of Interested Stockholders. Nothing contained in this Article V shall be construed to relieve any Interested Stockholder from any fiduciary obligation imposed by law. ARTICLE VI. STOCKHOLDER ACTION Any action required or permitted to be taken by the stockholders of the Corporation must be effected at a duly called annual or special meeting of such holders or by a consent in writing signed by the holders of all of the outstanding shares authorized to vote at such meeting. Except as otherwise required by law, special meetings of the stockholders of the Corporation may be called only by (i) the Board of Directors pursuant to a resolution approved by the affirmative vote of a majority of the Directors then in office, (ii) the Chairman of the Board, if one is elected, or (iii) the President; provided, however, that, if at the time of any such call there is an Interested Stockholder, such call shall also require the affirmative vote of a majority of the Continuing Directors then in office. Only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders of the Corporation, unless otherwise provided by law. Advance notice of any matters which stockholders intend to propose for action at an annual meeting shall be given in the manner provided in the By-Laws. 17 ARTICLE VII. DIRECTORS 1. General. All power of the Corporation shall be exercised by or under the direction of the Board of Directors except as otherwise provided herein or required by law. 2. Election of Directors. Election of Directors need not be by written ballot unless the By-Laws of the Corporation shall so provide. 3. Number, Election and Terms. 3A. Except as otherwise fixed pursuant to the provisions of Article IV hereof relating to the rights of the holders of any class or series of preferred stock to elect Directors, the number of Directors of the Corporation shall be fixed exclusively by resolution duly adopted from time to time by the affirmative vote of at least two-thirds of the Board of Directors. The Directors, other than those who may be elected by the holders of any class or series of preferred stock, shall be classified, with respect to the time for which they severally hold office, into two classes, as nearly equal in number as possible as determined by the Board of Directors, with one class to be elected annually. 3B. Commencing at the effective time of the merger of Strategic Diagnostics Inc. ("SDI") and EnSys Environmental Products, Inc. ("EnSys"), with the Corporation as the surviving corporation, and continuing through the 1998 annual meeting of stockholders of the Corporation, the Board of Directors shall consist of seven (7) members. The initial Board of Directors shall be elected as follows: EnSys and SDI will each select three (3) members of the Board of Directors and the remaining member of the Board of Directors will be selected by The Perkin-Elmer Corporation (the "Perkin-Elmer Corporation"). The Directors of the Corporation shall hold office as follows: the Class I Directors shall hold office for a term expiring at the 1997 annual meeting of the stockholders and the Class II Directors shall hold office for a term expiring at the 1998 annual meeting of stockholders, with the members of each class to hold office until their respective successors are duly elected and qualified. At each annual meeting of the stockholders of the Corporation, Directors elected to succeed those whose terms are expiring at that meeting shall be elected to hold office for a term expiring at the annual meeting of stockholders held in the second year following the year of their election and until their respective successors are duly elected and qualified. No decrease in the number of directors shall shorten the term of any incumbent director. 4. Stockholder Nominations of Director Candidates. Except as otherwise fixed pursuant to the provisions of Article IV hereof relating to the rights of the holders of any class of series of preferred stock to elect Directors, advance notice of nominations for the election of Directors, other than by the Board of Directors or a committee thereof, shall be given in the manner provided in the By-Laws. Notwithstanding the foregoing, all Class I Directors 18 holding office at the time of the 1997 annual meeting shall automatically be nominated, subject to such director's consent, to serve an additional two (2) year term expiring at the 1999 annual meeting of the stockholders of the Corporation and all Class II Directors holding office at the time of the 1998 annual meeting shall automatically be nominated, subject to such director's consent, to serve an additional two (2) year term expiring at the 2000 annual meeting of the stockholders of the Corporation. 5. Vacancies and Newly Created Directorships. Except as otherwise fixed pursuant to the provisions of Article IV hereof relating to the rights of the holders of any class or series of preferred stock to elect Directors, any vacancy occurring in the Board of Directors, including any vacancy created by reason of a newly created directorship resulting in an increase in the number of directors or any vacancy resulting from death, resignation, disqualification, removal or other causes, shall be filled solely by the affirmative vote of a majority of the remaining Directors then in office, if a quorum is present; provided, however, that, if there is an Interested Stockholder at the time of such vote, the filling of such vacancy shall also require the affirmative vote of a majority of the Continuing Directors then in office. Notwithstanding anything contained herein to the contrary, any Director that voluntarily leaves office may vote on his or her replacement. Any Director appointed in accordance with the preceding sentence shall hold office for the remainder of the full term of the class of Directors in which the new directorship was created or the vacancy occurred and until such Director's successor shall have been duly elected and qualified. When the number of Directors is increase or decreased, the Board of Directors shall determine the class or classes to which the increased or decreased number of Directors shall be apportioned. In the event of a vacancy in the Board of Directors, the remaining Directors, except as otherwise provided by law, may exercise the powers of the full Board of Directors until the vacancy is filled. 6. Removal. Except as otherwise fixed pursuant to the provisions of Article IV hereof relating to the rights of the holders of any class or series of preferred stock to elect Directors, any Director (including persons elected by Directors to fill vacancies in the Board of Directors) may be removed from office only with cause and by the affirmative vote of at least two-thirds of the total votes which would be eligible to be cast by stockholders in the election of such Director at a duly constituted meeting of stockholders called expressly for such purpose. A Director may not be removed from office without cause. At least 30 days prior to any meeting of stockholders at which it is proposed that any Director be removed from office, written notice shall be sent to the Director whose removal will be considered at the meeting. ARTICLE VIII. LIMITATION OF LIABILITY A Director of the Corporation shall not be personally liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a Director, except for liability (i) for any breach of the Director's duty of loyalty to the Corporation or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing 19 violation of law, (iii) under Section 174 of the General Corporation Law of Delaware, or (iv) for any transaction from which the Director derived an improper personal benefit. If the General Corporation Law of Delaware is amended after the effective date of this Certificate of Incorporation to authorize corporate action further eliminating or limiting the personal liability of directors, then the liability of a Director of the Corporation shall be eliminated or limited to the fullest extent permitted by the General Corporation Law of Delaware, as so amended. Any repeal or modification of this Article VIII (i) by the stockholders of the Corporation, or (ii) by an amendment to the General Corporation Law of Delaware shall not adversely affect any right or protection existing at the time of such repeal or modification with respect to any acts or omissions occurring either before or after such repeal or modification of a person serving as a Director at the time of such repeal or modification. ARTICLE IX. STANDARDS FOR BOARD OF DIRECTORS' EVALUATION OF OFFERS OR PROPOSALS The Board of Directors of the Corporation, when evaluating any offer or proposal of any person to (i) make a tender or exchange offer for any equity security of the Corporation or any subsidiary, (ii) merge or consolidate the Corporation or any subsidiary with another person, or (iii) purchase or otherwise acquire all or substantially all of the properties and assets of the Corporation or any subsidiary, may, in connection with the exercise of its judgment in determining what is in the best interests of the Corporation and its stockholders, give due consideration to all relevant factors, including without limitation, (a) the social and economic effects of acceptance of such offer or proposal on the employees of the Corporation and its subsidiaries, the suppliers, creditors, and customers of the Corporation and its subsidiaries, and the state, region, and communities in which the Corporation and its subsidiaries operate and are located, and (b) the long-term and short-term interests of the Corporation and its stockholders, including the possibility that these interests may be best served by the continued independence of the Corporation. ARTICLE X. AMENDMENT OF BY-LAWS The Board of Directors shall have the power to adopt, alter, amend and repeal the By-Laws of the Corporation. Any By-Laws of the Corporation adopted by the Directors under the powers conferred hereby may be altered, amended or repealed by the Directors or the stockholders. Notwithstanding the foregoing or any other provisions of this Certificate of Incorporation or the By-Laws of the Corporation to the contrary, such action by the Board of Directors shall require the affirmative vote of at least two-thirds of the Directors then in office. Notwithstanding the foregoing or any other provisions of this Certificate of Incorporation or the By-Laws of the Corporation to the contrary, any action by the stockholders to alter, amend or 20 repeal the By-Laws of the Corporation shall require the affirmative vote of at least two-thirds of the total votes eligible to be cast by stockholders with respect to such alteration, amendment or repeal, voting together as a single class, at a duly constituted meeting of stockholders called expressly for such purpose. ARTICLE XI. AMENDMENT OF CERTIFICATE OF INCORPORATION The Corporation reserves the right to repeal, alter or amend this Certificate of Incorporation in the manner now or hereafter prescribed by statute and this Certificate of Incorporation, and all rights conferred upon stockholders herein are granted subject to this reservation. No repeal, alteration or amendment of this Certificate of Incorporation shall be made unless the same is first approved by the Board of Directors of the Corporation pursuant to a resolution adopted by the affirmative vote of a majority of the Directors then in office, and thereafter approved by the stockholders. 21 -----END PRIVACY-ENHANCED MESSAGE-----