EXHIBIT 23.1

               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

      We consent to the incorporation by reference in the Registration
Statements (Form S-8 No. 333-86155, 333-86159, 333-45288, 333-63036 and
333-91996 pertaining to the LJL BioSystems, Inc. 1994 Equity Incentive Plan, LJL
BioSystems, Inc. 1997 Stock Plan, LJL BioSystems, Inc. 1998 Directors' Stock
Option Plan, 1995 Stock Option Plan, 1995 Non-Employee Directors' Stock Option
Plan, 1995 Employee Stock Purchase Plan and 2001 Stock Option Plan of Molecular
Devices Corporation of our report dated January 27, 2003, with respect to the
consolidated financial statements and schedule of Molecular Devices Corporation
included in the Annual Report (Form 10-K) for the year ended December 31, 2002.

                                                           /s/ Ernst & Young LLP

Palo Alto, California
March 25, 2003


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