August 14, 2025

Jason K. Garland
Chief Financial Officer
Repligen Corporation
41 Seyon Street
Building 1, Suite 100
Waltham, MA 02453

        Re: Repligen Corporation
            Form 10-K for Fiscal Year Ended December 31, 2024
            File No. 000-14656
Dear Jason K. Garland:

       We have limited our review of your filing to the financial statements
and related
disclosures and have the following comment.

       Please respond to this letter within ten business days by providing the
requested
information or advise us as soon as possible when you will respond. If you do
not believe a
comment applies to your facts and circumstances, please tell us why in your
response.

       After reviewing your response to this letter, we may have additional
comments.

Form 10-K for Fiscal Year Ended December 31, 2024
Note 5 - Acquisitions
2024 Acquisitions, page 88

1.     You have identified developed technology and goodwill from the Tantti
acquisition
       totaling $76 million. On page 14, you refer to patent assets acquired as
part of this
       acquisition and your policy footnote on page 83 refers to the estimated
fair value of
       customer relationships, developed technologies, trademark/tradename,
patents, non-
       compete agreements and in-process research and development from your
acquisitions.

       Given the significance of the allocation to goodwill and developed
technology, please
       tell us why you have not identified or assigned value to patents or
other intangible
       assets from this acquisition. Refer to ASC 805-20-55. As part of your
response,
       please include a general description of the procedures you follow to
identify
       intangible assets in your business acquisitions.
 August 14, 2025
Page 2

        In closing, 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 Gary Newberry at 202-551-3761 or Eric Atallah at
202-551-3663 with
any questions.



                                                          Sincerely,

                                                          Division of
Corporation Finance
                                                          Office of Life
Sciences