OpGen (OPGN) 8-K Changes in Registrant's Certifying Accountant

Exhibit 16.1

January 20, 2023

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Ladies and Gentlemen:

We have read Item 4.01 of Form 8-K dated January 20, 2023 of OpGen, Inc. and are in agreement with the statements contained therein.

/s/ CohnReznick LLP