REPLIGEN CORP — Director's Dealing 2007

Dec 21, 2007

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REPLIGEN CORP (RGEN)
CIK: 0000730272
Period of Report: 2007-12-12

Reporting Person: Henry Earl Webb (Director)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2007-12-12	Stock Option (Right to Buy)	$6.06	A	24000	Acquired	2017-12-12	Common stock (24000)	Direct

Footnotes

F1: 8,000 shares become exercisable on each of 12/12/2008, 12/12/2009 and 12/12/2010.