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                          June 24, 2020

       Oliver Schacht, Ph.D.
       Chief Executive Officer
       OpGen, Inc.
       708 Quince Orchard Road, Suite 205
       Gaithersburg, MD 20878

                                                        Re: OpGen, Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed June 17, 2020
                                                            File No. 333-239240

       Dear Dr. Schacht:

              This is to advise you that we have not reviewed and will not
review your registration
       statement.

               Please refer to Rules 460 and 461 regarding requests for
acceleration. 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.

                                                        Please contact Ada D.
Sarmento at 202-551-3798 with any questions.




                          Sincerely,


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Peter Jaslow, Esq.