Sangamo BioSciences Announces Publication in Nature of the Use of Zinc Finger Nucleases...

Sangamo BioSciences Announces Publication in Nature of the Use of Zinc Finger
Nucleases to Accelerate Precision Trait Stacking in Commercial Crop Species

RICHMOND, Calif., April 29 /PRNewswire-FirstCall/ -- Sangamo BioSciences, Inc.
(Nasdaq: SGMO) announced today continued success of its zinc finger
DNA-binding protein (ZFP) technology. New research published in the scientific
journal Nature by licensing partner Dow AgroSciences and Sangamo demonstrated
the successful application of ZFP technology for the efficient generation of
maize plants with multiple, commercially important traits. The techniques
described are broadly applicable across plant species and traits and establish
a new method for rapid and precise crop development.

In the study published in the Advance Online edition of Nature, scientists at
Dow AgroSciences and Sangamo used ZFP Nucleases (ZFNs(TM)) to introduce a
herbicide tolerance gene into a pre-determined address in the maize genome,
simultaneously eliminating the expression of an enzyme involved in the
production of phytate, a natural but undesirable compound found in feed crops
and a cause of environmental pollution. In a rapid, single step process the
gene involved in phytate production was disabled and permanently linked with
the acquisition of herbicide tolerance - i.e. stacking the two desired
characteristics in the plant and generating reduced phytate, herbicide
tolerant corn.

"These data reinforce that EXZACT(TM) Precision Technology has the potential
to redefine the future of agriculture driving productivity gains globally and
greatly enhancing sustainability in major food crops such as maize," said
Jerome Peribere, president and CEO of Dow AgroSciences. "This technology
provides flexibility and versatility in plant biotechnology research enabling
developers, such as Dow AgroSciences and our collaborators, to enhance the
discovery and development of novel traits for the crop production industry."

"The future of crop improvement lies in the ability to identify and
efficiently stack multiple, commercially valuable traits at predetermined
sites in the plant genome with absolute precision. With this technology, we
are taking the process of genome modification and trait development to a new
level of sophistication," said Vipula Shukla, project leader at Dow
AgroSciences. "We have demonstrated that EXZACT Precision Technology enables
us to rapidly develop new trait combinations in economically important crops,
including commodity crops, vegetables, ornamentals, trees and biomass crops.
The speed and precision of this approach, which will replace the random and
laborious approaches currently employed, can result in significant reduction
in the time and effort required to commercialize enhanced crops."

"These data are a powerful demonstration of the broad applicability of our ZFP
technology platform," stated Philip Gregory, D. Phil., Sangamo's vice
president of research. "Furthermore this is not simply a demonstration of
'cool science' in a model system but a real-life application of the technology
to provide a commercially relevant solution to a problem. Our ZFN gene editing
technology is being used to precisely and specifically disrupt, correct or add
genes to create novel cell lines and whole organisms - both plant and animal.
Today, ZFPs are being used to generate improved crops, powerful research
reagents and novel drugs for the treatment of intractable human diseases."

In June 2008 Dow AgroSciences exercised its option to become the exclusive
licensee and sublicensor of Sangamo's proprietary ZFP technology for the
development of products in plants and plant cell cultures following a
successful research collaboration that began in October 2005.

"It has been very rewarding to witness the rapid translation of our technology
into commercially relevant crop products," said Edward Lanphier, Sangamo's
president and chief executive officer. "The Dow AgroSciences team has done an
outstanding job of exploiting the powerful science of our ZFP platform."

About Sangamo
Sangamo BioSciences, Inc. is focused on the research and development of novel
DNA-binding proteins for therapeutic gene regulation and modification. The
most advanced ZFP Therapeutic(TM) development program is currently in Phase 2
clinical trials for evaluation of safety and clinical effect in patients with
diabetic neuropathy and ALS. Sangamo also has a Phase 1 clinical trial to
evaluate safety and clinical effect of a ZFP Therapeutic for the treatment of
HIV/AIDS. Other therapeutic development programs are focused on cancer,
neuropathic pain, nerve regeneration, Parkinson's disease and monogenic
diseases. Sangamo's core competencies enable the engineering of a class of
DNA-binding proteins known as zinc finger DNA-binding proteins (ZFPs). By
engineering ZFPs that recognize a specific DNA sequence Sangamo has created
ZFP transcription factors (ZFP TF(TM)) that can control gene expression and,
consequently, cell function. Sangamo is also developing sequence-specific ZFP
Nucleases (ZFN(TM)) for gene modification. Sangamo has established strategic
partnerships with companies in non-therapeutic applications of its technology
including Dow AgroSciences, Sigma-Aldrich Corporation and several companies
applying its ZFP technology to engineer cell lines for the production of
protein pharmaceuticals. For more information about Sangamo, visit the
company's web site at www.sangamo.com.

This press release may contain forward-looking statements based on Sangamo's
current expectations. These forward-looking statements include, without
limitation, references to the research and development of novel ZFP TFs and
ZFNs, human, plant and research applications of Sangamo's ZFP technology
platform, strategic partnerships with collaborators and clinical trials of ZFP
Therapeutics. Actual results may differ materially from these forward-looking
statements due to a number of factors, including technological challenges,
Sangamo's ability to develop commercially viable products and technological
developments by our competitors. See the company's SEC filings, and in
particular, the risk factors described in the company's Annual Report on Form
10-K and its most recent report on Form 10-Q. Sangamo BioSciences, Inc.
assumes no obligation to update the forward-looking information contained in
this press release.

EXZACT(TM) Precision Technology is a trademark of Dow AgroSciences LLC.

ZFP Therapeutic(TM), ZFP TF(TM) and ZFN(TM) are trademarks of Sangamo
BioSciences, Inc.

SOURCE Sangamo BioSciences, Inc.

Elizabeth Wolffe, Ph.D., of Sangamo BioSciences, Inc., +1-510-970-6000, ext.
271, ewolffe@sangamo.com