UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 5)*

HTG Molecular Diagnostics, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

40434H 10 4

(CUSIP Number)

Peter Haahr

Novo Holdings A/S

Tuborg Havnevej 19

Hellerup, Denmark DK-2900

+45 3527 6592

Copy to:

B. Shayne Kennedy, Esq.

Latham & Watkins LLP

650 Town Center Drive, 20^th Floor

Costa Mesa, CA 92626

Telephone: (714) 540-1235

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 24, 2017

(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 subject of this Schedule 13D, and is filing this statement because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box.  ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) 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 (the “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).

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This amendment (“Amendment No. 5”) amends the Schedule 13D originally filed with the Commission on May 13, 2015, as subsequently amended by Amendment No. 1 filed with the Commission on March 10, 2017, Amendment No. 2 filed with the Commission on March 31, 2017, Amendment No. 3 filed with the Commission on July 20, 2017 and Amendment No. 4 filed with the Commission on August 23, 2017 (collectively, the “Schedule”) to report a decrease in beneficial ownership of common stock of the Issuer held by the Reporting Person resulting from the sale of shares by Reporting Person. All capitalized terms contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Schedule.

Item 5. Interest in Securities of the Issuer

Item 5(a) of the Schedule is amended and replaced in its entirety as follows:

(a) Novo Holdings A/S beneficially owns an aggregate of 49,786 shares of the Issuer’s common stock subject to warrants (the “Novo Shares”), representing approximately 0.43% of the outstanding shares of common stock of the Issuer, based upon 11,448,443 shares of common stock outstanding as of August 4, 2017 as reported in the Issuer’s quarterly report (Form 10-Q) filed with the Commission on August 8, 2017.

Item 5(b) of the Schedule is amended and replaced in its entirety as follows:

(b) Novo Holdings A/S is a Danish limited liability company wholly owned by the Novo Nordisk Foundation. Novo Holdings A/S, through its Board of Directors (the “Novo Board”), has the sole power to vote and dispose of the 49,786 Novo Shares. The Novo Board, currently comprised of Sten Scheibye, Goran Ando, Jeppe Christiansen, Steen Riisgaard, Lars Rebien Sorensen and Per Wold-Olsen, may exercise voting and dispositive control over the Novo Shares only with the support of a majority of the Novo Board. As such, no individual member of the Novo Board is deemed to hold any beneficial ownership or reportable pecuniary interest in the Novo Shares. Except as described in this Amendment No. 5, neither the Foundation, Novo Holdings A/S nor their respective directors or executive officers has the power to direct the vote as to, or the disposition of the Novo Shares.

Item 5(c) of the Schedule is supplemented as follows:

(c) On August 23, 2017, Novo Holdings A/S sold 47,162 shares of the Issuer’s common stock in the open market through a broker’s transaction at a weighted average price of $2.0244 per share.

On August 24, 2017, Novo Holdings A/S sold 382,437 shares of the Issuer’s common stock in the open market through a broker’s transaction at a weighted average price of $1.9086 per share.

On August 25, 2017, Novo Holdings A/S sold 720,214 shares of the Issuer’s common stock in the open market through a broker’s transaction at a weighted average price of $1.7503 per share.

Item 5(e) of the Schedule is supplemented as follows:

(e) The Reporting Person ceased to be a beneficial owner of 5% or more on August 25, 2017.

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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.