EXHIBIT 5.1



                           [Cooley Godward Letterhead]


October 28, 2002


Lynx Therapeutics, Inc.
25861 Industrial Blvd.
Hayward, California  94545

Dear Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by Lynx Therapeutics, Inc. (the "Company") of a Registration
Statement on Form S-8 (the "Registration Statement") with the Securities and
Exchange Commission covering the offering of an aggregate of 600,000 shares of
the Company's Common Stock, $0.01 par value (the "Shares"), pursuant to the
Company's 1992 Stock Option Plan (the "Plan").

In connection with this opinion, we have examined the Registration Statement and
related Prospectus, your Amended and Restated Certificate of Incorporation and
Bylaws and such other documents, records, certificates, memoranda and other
instruments as we deem necessary as a basis for this opinion. We have assumed
the genuineness and authenticity of all documents submitted to us as originals,
the conformity to originals of all documents submitted to us as copies thereof,
and the due execution and delivery of all documents where due execution and
delivery are a prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Shares, when sold and issued in accordance with the Plan, the
Registration Statement and the related Prospectus, will be validly issued, fully
paid, and nonassessable (except as to shares issued pursuant to certain deferred
payment arrangements, which will be fully paid and nonassessable when such
deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

Cooley Godward LLP



By:  /s/ JAMES C. KITCH
     ------------------------------
     James C. Kitch