SC TO-T/A

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

Amendment No. 4

(Final Amendment)

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

ADEZA BIOMEDICAL CORPORATION

(Name of Subject Company (Issuer))

CYTYC CORPORATION

AUGUSTA MEDICAL CORPORATION

(Names of Filing Persons (Offerors))

Common Stock, par value $0.001 per share	006864 10 2
(Titles of classes of securities)	(CUSIP number of class of securities)

Patrick J. Sullivan

Chairman, President and Chief Executive Officer

Cytyc Corporation

250 Campus Drive, Marlborough, MA 01752

Tel: (508) 263-2900

(Name, address and telephone number of person authorized to receive notices and communications on behalf of the filing person)

Copies to:

Joseph E. Gilligan

Joseph G. Connolly, Jr.

Hogan & Hartson L.L.P.

Columbia Square

555 Thirteenth Street, N.W.

Washington, DC 20004-1109

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$496,745,664	$53,152

* Estimated for purposes of calculating the filing fee only. This amount assumes the purchase of up to 20,697,736 shares of common stock, par value $0.001 per share, of Adeza, at a purchase price of $24.00 per share. Such number of shares consists of, as of February 9, 2007, (i) 17,549,299 shares of common stock issued and outstanding and (ii) 3,148,437 shares of common stock that may be issued pursuant to all outstanding options and warrants to acquire Adeza shares.

** The amount of the filing fee, calculated in accordance with Rule 0-11 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), equals 0.000107 of the transaction valuation.

¨ Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:                Filing Party:

Form or Registration No.:              Date Filed:

¨ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

x third-party tender offer subject to Rule 14d-1.

¨ issuer tender offer subject to Rule 13e-4.

¨ going-private transaction subject to Rule 13e-3.

¨ amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer: x

AMENDMENT NO. 4 TO SCHEDULE TO

This Amendment No. 4 (this “Amendment”) amends and supplements the Tender Offer Statement on Schedule TO, as amended through the date hereof (as amended, the “Statement”), originally filed with the Securities and Exchange Commission (the “SEC”) on February 16, 2007, by (i) Cytyc Corporation, a Delaware corporation (“Cytyc”), and (ii) Augusta Medical Corporation, a Delaware corporation (the “Purchaser”) and a direct wholly-owned subsidiary of Cytyc, relating to the offer by the Purchaser to purchase all of the issued and outstanding shares of common stock, par value $0.001 per share (the “Shares”), of Adeza Biomedical Corporation, a Delaware corporation (“Adeza”), at a purchase price of $24.00 per Share, upon the terms and subject to the conditions set forth in the Offer to Purchase dated February 16, 2007 (the “Offer to Purchase”), and in the related Letter of Transmittal, copies of which were previously filed as Exhibits (a)(1)(A) and (a)(1)(B) to the Statement, respectively. Capitalized terms used and not otherwise defined in this Amendment shall have the meanings assigned to such terms in the Offer to Purchase or in the Statement.

Items 1-11.

Items 1, 4, 8 and 11 of the Statement, which incorporate by reference the information contained in the Offer to Purchase, are hereby amended and supplemented by adding the following text thereto:

“The subsequent offering period expired at 12:00 midnight, New York City time, on March 30, 2007. The Depositary has advised Cytyc that, as of the expiration of the subsequent offering period, 16,816,572 Shares were validly tendered and not withdrawn in the Offer, representing approximately 96% of Adeza’s issued and outstanding Shares. All validly tendered Shares have been accepted for payment in accordance with the terms of the Offer.

“The Purchaser intends to complete the acquisition of Adeza through a short form merger as soon as practicable. In the short form merger, all outstanding Shares not purchased by the Purchaser in the Offer, and not held by a holder who demands appraisal rights for such shares under the Delaware General Corporation Law, will be converted into the right to receive $24.00 per share in cash.

“On April 2, 2007, Cytyc issued a press release announcing the results of the Offer. The full text of the April 2, 2007 press release is attached as Exhibit (a)(1)(M) and is incorporated herein by reference.”

Items 12. Exhibits.

Item 12 of the Statement is amended and supplemented by adding the following:

“(a)(1)(M) Press Release issued by Cytyc on April 2, 2007.”

SIGNATURES

After due 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.

AUGUSTA MEDICAL CORPORATION
By:	/s/ Patrick J. Sullivan
Name:	Patrick J. Sullivan
Title:	President
CYTYC CORPORATION
By:	/s/ Patrick J. Sullivan
Name:	Patrick J. Sullivan
Title:	Chairman, President and Chief Executive Officer

Date: April 2, 2007

INDEX TO EXHIBITS

Exhibit No.	Description
(a)(1)(A)	Offer to Purchase, dated as of February 16, 2007.*
(a)(1)(B)	Letter of Transmittal.*
(a)(1)(C)	Notice of Guaranteed Delivery.*
(a)(1)(D)	Letter to Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(E)	Letter to Clients for use by Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(F)	Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9.*
(a)(1)(G)	Press Release issued by Cytyc on February 12, 2007 (incorporated by reference to the Schedule TO-C filed by Cytyc with the SEC on February 12, 2007).
(a)(1)(H)	Transcript of a conference call held by Cytyc on February 12, 2007 (incorporated by reference to the Schedule TO-C filed by Cytyc with the SEC on February 13, 2007).
(a)(1)(I)	Summary Advertisement published on February 16, 2007.*
(a)(1)(J)	Press Release issued by Cytyc on March 14, 2007.*
(a)(1)(K)	Press Release issued by Cytyc on March 19, 2007.*
(a)(1)(L)	Press Release issued by Cytyc on March 22, 2007.*
(a)(1)(M)	Press Release issued by Cytyc on April 2, 2007.
(d)(1)	Agreement and Plan of Merger, dated as of February 11, 2007, among Cytyc, the Purchaser and Adeza (incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K filed by Cytyc with the SEC on February 13, 2007).
(d)(2)	Form of Stockholder Agreement (Tender).*
(d)(3)	Form of Stockholder Agreement (Non-Tender).*
(d)(4)	Confidentiality Agreement, dated as of January 26, 2007, by and between Adeza and Cytyc.*

* Previously filed

EX-99.A.1.M

Exhibit (a)(1)(M)

Contact: Tim Adams, Chief Financial Officer

Anne Rivers, Investor Relations

Jeff Keene, Healthcare Media

Cytyc Corporation: 508-263-8765

www.cytyc.com

Stephanie Carrington

The Ruth Group: 646-536-7017

Shanti Skiffington/Wendy Ryan

Schwartz Communications: 781-684-0770

CYTYC COMPLETES CASH TENDER OFFER FOR ADEZA BIOMEDICAL CORPORATION

Marlborough, Mass., April 2, 2007 – Cytyc Corporation (Nasdaq: CYTC) today announced the completion of the tender offer by its direct wholly-owned subsidiary, Augusta Medical Corporation, for all outstanding shares of Adeza Biomedical Corporation (Nasdaq:ADZA) at a price of $24.00 per share in cash.

The subsequent offering period expired at 12:00 midnight, New York City time, on Friday, March 30, 2007. The initial tender offer period expired at 12:00 midnight, New York City time, on Friday, March 16, 2007.

The depositary for the tender offer has advised Cytyc that, as of the expiration of the subsequent offering period, 16,816,572 shares were validly tendered and not withdrawn in the tender offer, representing approximately 96% of Adeza’s issued and outstanding shares. All validly tendered shares have been accepted for payment in accordance with the terms of the tender offer.

Cytyc intends to complete the acquisition of Adeza through a short form merger as soon as practicable. In the short form merger, all outstanding Adeza shares not purchased in the tender offer, and not held by a holder who demands appraisal rights for such shares under the Delaware General Corporation Law, will be converted into the right to receive $24.00 per share in cash. Following the merger, detailed instructions will be mailed to Adeza stockholders who did not tender in the offer outlining the steps to be taken to obtain the merger consideration.

About Cytyc

Cytyc Corporation is a diversified diagnostic and medical device company that designs, develops, manufactures, and markets innovative and clinically effective diagnostic and surgical products. Cytyc’s products cover a range of cancer and women’s health applications, including cervical cancer screening, treatment of excessive menstrual bleeding, radiation treatment of early-stage breast cancer, and radiation treatment of patients with malignant brain tumors.

Cytyc is traded on The NASDAQ Global Select Market under the symbol CYTC. Cytyc is a registered trademark of Cytyc Corporation.

Forward-Looking Statements

Forward-looking statements in this press release are made pursuant to the provisions of Section 21E of the Securities Exchange Act of 1934. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements relating to the expected benefits of the transaction, Cytyc’s future financial condition, operating results and economic performance, and management’s expectations regarding key customer relationships, future growth opportunities, product acceptance and business strategy, constitute forward-looking statements. These statements are based on current expectations, forecasts and assumptions of Cytyc and Adeza that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from those statements. Risks and uncertainties include, among others, the risk that the conditions to the merger set forth in the merger agreement will not be satisfied, changes in either companies’ businesses during the period between now and the closing, the successful integration of Adeza into Cytyc’s business subsequent to the closing of the transaction, adverse reactions to the proposed transaction by customers, suppliers, and strategic partners, dependence on key personnel and customers as well as reliance on proprietary technology, uncertainty of product development efforts and timelines, management of growth, product diversification, and organizational change, entry into new market segments domestically, such as pharmaceuticals, and new markets internationally, risks associated with litigation, the successful consummation of planned acquisition transactions, the effective integration of acquired businesses and technologies, competition and competitive pricing pressures, risks associated with the FDA regulatory approval processes and healthcare reimbursement policies in the United States and abroad, introduction of technologies that are disruptive to Cytyc’s business and operations, the potential consequences of the Cytyc Audit Committee’s voluntary review of circumstances relating to certain employee stock option exercises, including the impact of the expected restatement of Cytyc’s financial statements, the associated costs and expenses, and any regulatory review or litigation relating to such matters, the impact of new accounting requirements and governmental rules and regulations, as well as other risks detailed in Cytyc’s and Adeza’s filings with the SEC, including those under the heading “Risk Factors” in Cytyc’s 2006 Annual Report on Form 10-K and Adeza’s 2006 Annual Report on Form 10-K, all as filed with the SEC. Cytyc cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date they were made. Cytyc disclaims any obligation to publicly update or revise any such statements to reflect any change in its expectations or events, conditions, or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements.

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