EX-24.1 2 rrd164516_185935.htm POWER OF ATTORNEY

rrd164516_185935.html

				LIMITED POWER OF ATTORNEY
						FOR
				FORM ID AND SECTION 16(a) FILINGS

          Know all by these presents, that the undersigned hereby constitutes and appoints Walter
Herlihy, Laura Whitehouse Pew, Robert Puopolo and Sarah Carmody the undersigned's true and
lawful attorney-in-fact to:

(1) execute and file with the United States Securities and Exchange Commission ("SEC") for and
on behalf of the undersigned a Form ID and to receive any and all information provided by the SEC
to the undersigned pursuant to such application;

(2) execute for and on behalf of the undersigned, in the undersigned's capacity as an officer, director
and/or stockholder of Repligen Corporation (the "Company"), Forms 3, 4, and 5 and amendments
thereto in accordance with Section 16(a) of the Securities Exchange Act of 1934 and the rules
thereunder;

(3) do and perform any and all acts for and on behalf of the undersigned which may be necessary or
desirable to complete and execute any such Form 3, 4, or 5 and any amendments thereto and timely
file such forms with the SEC and any stock exchange or similar authority; and

(4) take any other action of any type whatsoever which, in the opinion of such attorney-in-fact, may
 be necessary or desirable in connection with the foregoing authority,  it being understood that the
documents executed by such attorney-in-fact on behalf of the undersigned pursuant to this Power of
Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to such attorney-in-fact full power and authority to do and perform
any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights
and powers herein granted.  The undersigned acknowledges that the foregoing attorney-in-fact, in
serving in such capacity at the request of the undersigned, is not assuming, nor is the Company
assuming, any of  the undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

	This Power of Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4, and 5 with respect to the undersigned's holdings of and
transactions in securities issued by the Company, unless earlier revoked by the undersigned in a
signed writing delivered to the foregoing attorney-in-fact.   This Power of Attorney may be filed
with the SEC as a confirming statement of the authority granted herein.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed
as of this 19th day of December, 2007.

				 By: /s/ Earl Webb Henry