February 4, 2020

Evan Jones
Chief Executive Officer
OpGen, Inc.
708 Quince Orchard Road, Suite 205
Gaithersburg, MD 20878

       Re: OpGen, Inc.
           Registration Statement on Form S-3
           Filed January 28, 2020
           File No. 333-236106

Dear Mr. Jones:

       We have limited our review of your registration statement to those
issues we have
addressed in our comment. In our comment, we may ask you to provide us with
information so
we may better understand your disclosure.

       Please respond to this letter by amending your registration statement
and providing the
requested information. If you do not believe our comment applies to your facts
and
circumstances or do not believe an amendment is appropriate, please tell us why
in your
response.

       After reviewing any amendment to your registration statement and the
information you
provide in response to our comment, we may have additional comments.

Registration Statement on Form S-3 filed January 28, 2020

Exclusive Jurisdiction for Certain Actions, page 37

1.     Although we note your undertaking, in your response to comment 17 of our
comment
       letter dated December 12, 2019, to include similar disclosure as
provided in response to
       that comment with regard to your forum selection provision in your
future Exchange Act
       and Securities Act filings in which such provision is addressed, we do
note see such
       disclosure in your filing at this time. As such, we continue to note
that your forum
       selection provision identifies the Court of Chancery of the State of
Delaware as the sole
       and exclusive forum for certain litigation, including any "derivative
action." Please
       disclose whether this provision applies to actions arising under the
Securities Act or
       Exchange Act. In that regard, we note that Section 27 of the Exchange
Act creates
       exclusive federal jurisdiction over all suits brought to enforce any
duty or liability created
 Evan Jones
OpGen, Inc.
February 4, 2020
Page 2
         by the Exchange Act or the rules and regulations thereunder, and
Section 22 of the
         Securities Act creates concurrent jurisdiction for federal and state
courts over all suits
         brought to enforce any duty or liability created by the Securities Act
or the rules and
         regulations thereunder. If the provision applies to Securities Act
claims, please also revise
         your prospectus to state that there is uncertainty as to whether a
court would enforce such
         provision and that investors cannot waive compliance with the federal
securities laws and
         the rules and regulations thereunder. If this provision does not apply
to actions arising
         under the Securities Act or Exchange Act, please also ensure that the
exclusive forum
         provision in the governing documents states this clearly, or tell us
how you will inform
         investors in future filings that the provision does not apply to any
actions arising under the
         Securities Act or Exchange Act.
        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration
statement.

       Please contact Tim Buchmiller at (202) 551-3635 or Suzanne Hayes at
(202) 551-3675
with any questions.



FirstName LastNameEvan Jones                                    Sincerely,
Comapany NameOpGen, Inc.
                                                                Division of
Corporation Finance
February 4, 2020 Page 2                                         Office of Life
Sciences
FirstName LastName