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                                    EXHIBIT 5

             OPINION AND CONSENT OF BROBECK, PHLEGER & HARRISON LLP

                                 April 6, 2000

Sangamo BioSciences, Inc.
501 Canal Boulevard, Suite A100
Richmond, California 94804

               Re: Sangamo BioSciences, Inc.- Registration Statement on Form S-8

Dear Ladies and Gentlemen:

               We have acted as counsel to Sangamo BioSciences, Inc., a Delaware
Corporation (the "Company"), in connection with the registration on Form S-8
(the "Registration Statement") under the Securities Act of 1933, as amended, of
(i) 3,635,832 shares of Common Stock under the Company's 2000 Stock Incentive
Plan (the "Incentive Plan"), and (ii) 400,000 shares of Common Stock under the
Company's 2000 Employee Stock Purchase Plan (the "Purchase Plan"). All of such
shares are collectively referred to herein as the "Shares".

               This opinion is being furnished in accordance with the
requirements of Item 8 of Form S-8 and Item 601(b)(5)(i) of Regulation S-K.

               We have reviewed the Company's charter documents and the
corporate proceedings taken by the Company in connection with the establishment
of the Incentive Plan and the Purchase Plan. Based on such review, we are of the
opinion that, if, as and when the Shares have been issued and sold (and the
consideration therefor received) pursuant to the (a) provisions of option
agreements duly authorized under the Incentive Plan and in accordance with the
Registration Statement, (b) duly authorized direct stock issuances effected
under the Incentive Plan and in accordance with the Registration Statement, or
(c) duly authorized stock purchase agreements under the Purchase Plan and in
accordance with the Registration Statement, such Shares will be duly authorized,
legally issued, fully paid and nonassessable.

               We consent to the filing of this opinion letter as Exhibit 5 to
the Registration Statement.

               This opinion letter is rendered as of the date first written
above and we disclaim any obligation to advise you of facts, circumstances,
events or developments which hereafter may be brought to our attention and which
may alter, affect or modify the opinion expressed herein. Our opinion is
expressly limited to the matters set forth above and we render no opinion,
whether by implication or otherwise, as to any other matters relating to the
Company, the Incentive Plan, the Purchase Plan, or the Shares.

                                        Very truly yours,

                                        /s/ BROBECK, PHLEGER & HARRISON LLP
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                                            BROBECK, PHLEGER & HARRISON LLP