<SEC-DOCUMENT>0000950170-25-074224-index.html : 20250519
<SEC-HEADER>0000950170-25-074224.hdr.sgml : 20250519
<ACCEPTANCE-DATETIME>20250519150544
ACCESSION NUMBER:		0000950170-25-074224
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20250515
FILED AS OF DATE:		20250519
DATE AS OF CHANGE:		20250519

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Madaus Martin D
		CENTRAL INDEX KEY:			0001310268
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14656
		FILM NUMBER:		25963509

	MAIL ADDRESS:	
		STREET 1:		290 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821

ISSUER:		

	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
		EIN:				042729386
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>4
<TEXT>
Document 1 - file: ownership.html

Document 1 - RAW XML: ownership.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.1
<SEQUENCE>2
<FILENAME>rgen-ex24_1.htm
<DESCRIPTION>EX-24.1
<TEXT>
Document 2 - file: rgen-ex24_1.htm

</DOCUMENT>
</SEC-DOCUMENT>