Exhibit 99.1

    SANGAMO BIOSCIENCES APPOINTS MARGARET LIU, M.D. TO ITS BOARD OF DIRECTORS

   WILLIAM J. RUTTER, PH.D. RETIRES FROM BOARD FOLLOWING FIVE YEARS OF SERVICE

    RICHMOND, Calif., March 9 /PRNewswire-FirstCall/ -- Sangamo BioSciences,
Inc. (Nasdaq: SGMO), a leader in the research and development of novel zinc
finger DNA-binding proteins (ZFPs) for therapeutic gene regulation and
modification, announced today the appointment of Margaret Liu, M.D. to its Board
of Directors, effective March 4, 2005.

    Dr. Liu is an accomplished leader in the research and development of vaccine
and immunization programs for infectious diseases, particularly HIV, and in the
field of gene-based therapies. She has served as Senior Director at Merck
Research Laboratories in the Department of Virus and Cell Biology, Vice
President of Vaccines Research and Gene Therapy at Chiron Corporation, and
Senior Advisor in Vaccinology at the Bill and Melinda Gates Foundation.

    "It is an honor to have Dr. Margaret Liu join Sangamo's board. She is a
luminary in infectious diseases and Sangamo will benefit enormously from her
insight as we advance the therapeutic applications of our ZFP technology. Her
extensive experience in the pharmaceutical and biotechnology industries will aid
us in the clinical and commercial development of our ZFP Therapeutic(TM)
programs," stated Edward Lanphier, President and Chief Executive Officer at
Sangamo BioSciences.

    "I am very excited to join the Board of Directors of Sangamo BioSciences,"
commented Dr. Liu. "Sangamo has developed and established an important new
therapeutic product development platform based upon targeting endogenous genes
with engineered ZFPs. I am particularly enthusiastic about lending my experience
towards Sangamo's research in the development of a potential HIV/AIDS therapy,
which uses their technology to disrupt the CCR5 receptor in the CD4 T-cells of a
patient with HIV and could ultimately protect the patient from progressive HIV
infection."

    Margaret A. Liu earned her B.A. in Chemistry, Summa Cum Laude, from Colorado
College and an M.D. from Harvard Medical School. She completed Internship and
Residency in Internal Medicine and a Fellowship in Endocrinology at
Massachusetts General Hospital. She received Board Certification in Internal
Medicine and in Endocrinology and Metabolism. Dr. Liu was a Visiting Scientist
at the Massachusetts Institute of Technology and an instructor at Harvard
Medical School.

    Dr. Liu is currently Visiting Professor at the Karolinska Institutet in
Stockholm and Vice-Chairman of the Board of Transgene in Strasbourg. In addition
to these duties, she serves as a member of the NIH NIAID Council (an appointment
made by the US Secretary of Health and Human Services), chairman of the
Scientific Advisory Group of the International Vaccine Institute (in Seoul), a
member of the Board of Directors of the Keystone Symposia, scientific advisor
for AVAC (the AIDS Vaccine Advocacy Coalition), a member of the Advisory Board
for the Elizabeth Glazer Pediatric AIDS Foundation Scholars



Award, and a member of the External Scientific Advisory Committee of the
Children's Hospital Oakland Research Institute. She is a former member of the
following organizations: the European Developing Country Clinical Trials
Partnership (EDCTP) Board, the WHO IVR VAC (WHO's Initiative for Vaccine
Research, Vaccine Advisory Committee), and the GAVI R&D Task Force during its
tenure.

    Dr. Liu is a founding editor or on the editorial board or advisory boards of
various scientific journals and has been elected a member of the American
Society for Clinical Investigation and a Fellow of the Molecular Medicine
Society. In 2002, Discover magazine named Dr. Liu one of "The 50 Most Important
Women Scientists." Her pioneering work in the area of DNA vaccines has led to
her receipt of an honorary Doctorate of Science from Colorado College and
numerous honorary lectureships.

    A member of Sangamo's board for the last five years, William J. Rutter,
Ph.D. announced that he is leaving, effective March 4, 2005, to devote more time
to several early stage technology companies of which he is a founder and
principal supporter. Dr. Rutter is the co-founder of Chiron Corporation and
served as its Chairman of the Board from Chiron's inception in 1981 until 1999.
"I speak for the company and personally when I say that we are deeply indebted
to Bill for his contributions to Sangamo over the last five years," stated
Edward Lanphier. "We have benefited tremendously from his experience and insight
as one of the founders of the biotechnology industry and I wish him all the very
best in his many ventures."

    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 development programs are currently in Phase I
clinical trials for evaluation of safety in patients with peripheral artery
disease and diabetic neuropathy. Other therapeutic development programs are
focused on ischemic heart disease, congestive heart failure, cancer, neuropathic
pain, and infectious 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 therapeutic gene
modification as a treatment and possible cure for a variety of monogenic
diseases such as sickle cell anemia and for infectious diseases such as HIV. For
more information about Sangamo, visit the company's web site at www.sangamo.com
or www.expressinglife.com.

    This press release contains forward-looking statements regarding Sangamo's
current expectations. These statements are not guarantees of future performance
and are subject to certain risks, uncertainties and assumptions that are
difficult to predict. Factors that could cause actual results to differ include
the early stage of ZFP Therapeutic development, uncertainties related to the
timing of initiation and completion of clinical trials, and whether clinical
trial results will validate and support the safety and efficacy of ZFP
Therapeutics. Further, there can be no assurance that the necessary regulatory
approvals will be obtained or that Sangamo will be able



to develop commercially viable gene based therapeutics. Actual results may
differ from those projected in forward-looking statements due to risks and
uncertainties that exist in the company's operations and business environments.
These risks and uncertainties are described more fully in the company's' Annual
Reports on Form 10-K and Quarterly Reports on Form 10-Q as filed with the
Securities and Exchange Commission. Forward-looking statements contained in this
announcement are made as of this date and will not be updated.

SOURCE  Sangamo BioSciences, Inc.
    -0-                             03/09/2005
    /CONTACT:  Elizabeth Wolffe, Ph.D., of Sangamo BioSciences, Inc.,
+1-510-970-6000, ext. 271, or ewolffe@sangamo.com; or media, Kathy Nugent,
+1-212-213-0006, or investors, John Cummings, +1-415-352-6262, both of Burns
McClellan, Inc., for Sangamo BioSciences, Inc./
    /Web site:  http://www.sangamo.com /
    (SGMO)