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[WILSON SONSINI GOODRICH & ROSATI LETTERHEAD]
EXHIBIT 5.1
September 29, 2000
Ciphergen Biosystems, Inc.
6611 Dumbarton Circle
Fremont, CA 94555
RE: REGISTRATION ON FORM S-1
Ladies and Gentlemen:
We have examined the Registration Statement on Form S-1 filed by Ciphergen
Biosystems, Inc. (the "Company") with the Securities and Exchange Commission on
September 29, 2000 (the "Registration Statement"), in connection with the
registration under the Securities Act of 1933, as amended (the "Act"), of up to
575,000 shares of the Company's Common Stock, $0.001 par value per share (the
"Shares"). The Shares include an over-allotment option granted to the
underwriters of the offering to purchase up to 75,000 shares. The shares will be
offered for sale to the public by the Underwriters together with shares of the
same class registered pursuant to the Company's Registration Statement on Form
S-1, as amended (File No. 333-32812), which was declared effective on
September 28, 2000 (the "Initial Registration Statement"). As the Company's
legal counsel, we have examined the proceedings taken, and are familiar with the
proceedings proposed to be taken, by the Company in connection with the sale and
issuance of the Shares.
Based on the foregoing, it is our opinion that the Shares, when issued and
sold in the manner described in the Registration Statement, will be legally and
validly issued, fully paid and non-assessable.
We are members of the Bar of the State of California only and express no
opinion as to any matter relating to the laws of any jurisdiction other than the
laws of the State of California, the Delaware General Corporation Law and the
federal laws of the United States.
We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the
Registration Statement, including the Prospectus constituting a part thereof, as
such may be amended or supplemented, or incorporated by reference in any
Registration Statement relating to the prospectus filed pursuant to Rule 462(b)
of the Act.
Very truly yours,
WILSON SONSINI GOODRICH & ROSATI
/s/ WILSON SONSINI GOODRICH & ROSATI
