REPLIGEN CORP — Director's Dealing 2008

Mar 6, 2008

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REPLIGEN CORP (RGEN)
CIK: 0000730272
Period of Report: 2008-03-04

Reporting Person: WITT DANIEL P (Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2008-03-04	Common Stock	S	100	$5.52	Disposed	44734	Indirect
2008-03-04	Common Stock	S	1700	$5.50	Disposed	43034	Indirect
2008-03-04	Common Stock	S	617	$5.41	Disposed	42417	Indirect
2008-03-04	Common Stock	S	717	$5.39	Disposed	41700	Indirect
2008-03-04	Common Stock	S	883	$5.38	Disposed	40817	Indirect
2008-03-04	Common Stock	S	100	$5.34	Disposed	40717	Indirect
2008-03-04	Common Stock	S	600	$5.32	Disposed	40117	Indirect
2008-03-04	Common Stock	S	140	$5.29	Disposed	39977	Indirect
2008-03-04	Common Stock	S	143	$5.28	Disposed	39834	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	38300	Direct

Footnotes

F1: Sale by wife pursuant to distribution of marital assets in divorce settlement.

F2: The reporting person and his wife have entered into a binding divorce settlement agreement providing for a divorce as well as a distribution of marital assets. The divorce will become final after a 90-day waiting period imposed pursuant to state law. The reporting person and his wife currently maintain separate households. Therefore, the reporting person disclaims beneficial ownership of these shares.