SANGAMO ANNOUNCES SALE OF $20.5 MILLION OF COMMON STOCK TO INSTITUTIONAL AND STRATEGIC INVESTORS

Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that it has obtained commitments from a select group of institutional investors and Dow AgroSciences, LLC to purchase approximately 5.08 million shares of common stock, at a price of $3.85 per share, for gross proceeds of approximately $19.5 million, before fees and expenses. The closing is expected to take place on Wednesday, November 16, 2005, subject to the satisfaction of customary closing conditions.

PR Newswire (http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/story/11-11-2005/0004213851&EDATE=)