REPLIGEN CORP — Director's Dealing 2013

Mar 27, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REPLIGEN CORP (RGEN)
CIK: 0000730272
Period of Report: 2013-03-26

Reporting Person: WITT DANIEL P (Senior Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-03-26	Common Stock	M	10000	$5.51	Acquired	55707	Direct
2013-03-26	Common Stock	F	7998	$6.89	Disposed	47709	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-03-26	Stock Option (Right to Buy)	$5.51	M	10000	Disposed	2013-04-23	Common Stock (10000)	Direct

Footnotes

F1: Payment made via forfeiture of 7,998 shares of Common Stock valued at the Closing Price of $6.89 on March 26, 2013.