SUPPLEMENT TO PROXY STATEMENT FOR THE ANNUAL MEETING OF STOCKHOLDERS

TO BE RECONVENED ON SEPTEMBER 15, 2022

Dear Stockholder:

This proxy statement supplement, dated August 18, 2022 (this “Supplement”), supplements the definitive proxy statement on Schedule 14A of HTG Molecular Diagnostics, Inc., a Delaware corporation (the “Company”), filed with the Securities and Exchange Commission on July 7, 2022 (the “Proxy Statement”) for the 2022 Annual Meeting of Stockholders of the Company held on August 17, 2022 at 1:00 p.m. Pacific Time and to be reconvened on September 15, 2022 at 1:00 p.m. Pacific Time virtually via live audio-only webcast at www.proxydocs.com/HTGM (the “annual meeting). Capitalized terms used and not defined herein have the meanings given to them in the Proxy Statement.

THIS SUPPLEMENT SHOULD BE READ IN CONJUNCTION WITH THE PROXY STATEMENT. TO THE EXTENT INFORMATION IN THIS SUPPLEMENT UPDATES OR CONFLICTS WITH INFORMATION CONTAINED IN THE PROXY STATEMENT, THE INFORMATION IN THIS SUPPLEMENT IS THE MORE CURRENT INFORMATION. WE URGE YOU TO CAREFULLY READ THIS SUPPLEMENT, TOGETHER WITH THE PROXY STATEMENT.

Adjournment; Reduction in Quorum Requirement

On August 17, 2022, the Company adjourned the annual meeting without any business being conducted due to a lack of quorum. As stated in the Proxy Statement, the requisite quorum for the annual meeting was a majority of the shares of stock outstanding and entitled to vote on the record date. On August 17, 2022, the chair of the meeting adjourned the annual meeting until 1:00 p.m. Pacific Time on September 15, 2022. The record date remains June 21, 2022. The purposes for which the annual meeting is being held remain the same as those listed in the Proxy Statement.

To facilitate the achievement of a quorum, on August 18, 2022, the Board approved an amendment to the Company’s bylaws to reduce the quorum requirement for all meetings of stockholders, including the annual meeting, from a majority of the stock outstanding and entitled to vote to one-third of the stock outstanding and entitled to vote.

On the record date for the annual meeting, there were 11,045,986 shares outstanding and entitled to vote. As a result of the foregoing amendment to the bylaws, the holders of at least 3,681,996 shares must be present virtually or represented by proxy at the annual meeting to have a quorum.

Resignation of Directors; Appointment of Director and Committee Members; Option Modifications

James T. LaFrance’s term of office was scheduled to expire at the annual meeting. In addition, Harry A. George previously submitted his resignation from the Board, effective on the date of the annual meeting. In light of the adjournment of the annual meeting until September 15, 2022, on August 17, 2022, each of Mr. LaFrance and Mr. George resigned from the Board, effective on August 18, 2022. In connection with their resignations, the Board approved modifications to extend the deadline to exercise the stock options held by Mr. LaFrance and Mr. George from the date that is three months following their resignation to the respective expirations of the 10-year terms of the options. The modifications will be accounted for as a non-cash compensation expense based on a calculation of the fair value at the time of the modification, and will be determined in accordance with ASC Topic 718 for stock-based compensation transactions. The aggregate number of shares currently subject to outstanding stock options held by Mr. LaFrance is 10,798 shares, at a weighted average exercise price of $15.00 per share. The aggregate number of shares currently subject to outstanding stock options held by Mr. George is 10,532 shares, at a weighted average exercise price of $13.30 per share.

On August 18, 2022, the Board appointed Thomas W. Dubensky Jr., Ph.D. to the Board, effective concurrently with the resignation of Mr. LaFrance, to serve as a Class I director with a term of office expiring at the annual meeting. Dr. Dubensky was also appointed to serve as a member of the Compensation Committee of the Board. Dr. Dubensky is named in the Notice and proxy materials for the annual meeting as a nominee for election at the meeting. The Board also appointed Lee R. McCracken to serve as a member of the Audit Committee of the Board.