<SEC-DOCUMENT>0001969223-24-000139.txt : 20240223
<SEC-HEADER>0001969223-24-000139.hdr.sgml : 20240223
<ACCEPTANCE-DATETIME>20240223152936
ACCESSION NUMBER:		0001969223-24-000139
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20240223
DATE AS OF CHANGE:		20240223

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			REPLIGEN CORP
		CENTRAL INDEX KEY:			0000730272
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				042729386
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	000-14656
		FILM NUMBER:		24670763

	BUSINESS ADDRESS:	
		STREET 1:		41 SEYON STREET
		STREET 2:		BUILDING 1, SUITE 100
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453
		BUSINESS PHONE:		7814499560

	MAIL ADDRESS:	
		STREET 1:		41 SEYON STREET
		STREET 2:		BUILDING 1, SUITE 100
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Bylund James
		CENTRAL INDEX KEY:			0001849642
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		C/O REPLIGEN CORPORATION
		STREET 2:		41 SYON ST. BLDG. SUITE 100
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001849642</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000730272</issuerCik>
      <issuerName>Repligen Corporation</issuerName>
      <secFileNumber>000-14656</secFileNumber>
      <issuerAddress>
        <com:street1>41 Seyon Street, Bldg. 1</com:street1>
        <com:street2>Suite 100</com:street2>
        <com:city>Waltham</com:city>
        <com:stateOrCountry>MA</com:stateOrCountry>
        <com:zipCode>02453</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>781-250-0111</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>James Bylund</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>UBS Financial Services Inc</name>
        <address>
          <com:street1>1000 Harbor Blvd</com:street1>
          <com:street2>3rd Floor</com:street2>
          <com:city>Weehawken</com:city>
          <com:stateOrCountry>NJ</com:stateOrCountry>
          <com:zipCode>07086</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>4373</noOfUnitsSold>
      <aggregateMarketValue>865854</aggregateMarketValue>
      <noOfUnitsOutstanding>55771075</noOfUnitsOutstanding>
      <approxSaleDate>02/23/2024</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>04/01/2021</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>640</amountOfSecuritiesAcquired>
      <paymentDate>04/01/2021</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>02/24/2022</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>373</amountOfSecuritiesAcquired>
      <paymentDate>02/24/2022</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>04/01/2022</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>665</amountOfSecuritiesAcquired>
      <paymentDate>04/01/2022</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>02/24/2023</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>344</amountOfSecuritiesAcquired>
      <paymentDate>02/24/2023</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>02/24/2023</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>745</amountOfSecuritiesAcquired>
      <paymentDate>02/24/2023</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>common</securitiesClassTitle>
      <acquiredDate>04/01/2023</acquiredDate>
      <natureOfAcquisitionTransaction>RSU Vest</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>666</amountOfSecuritiesAcquired>
      <paymentDate>04/01/2023</paymentDate>
      <natureOfPayment>N/A</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>commmon</securitiesClassTitle>
      <acquiredDate>02/23/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Stock Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>940</amountOfSecuritiesAcquired>
      <paymentDate>02/23/2024</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <remarks>Selling shares that were the result of RSU vestings where no cash consideration was paid.  There is also one lot of options executed in a same day sale transaction.  Table I: Securities To Be Sold Addendum is attached.</remarks>
    <noticeSignature>
      <noticeDate>02/23/2024</noticeDate>
      <signature>/s/ UBS Financial Services Inc, as attorney-in-fact for James Bylund</signature>
    </noticeSignature>
  </formData>
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</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
