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. 33-99200 and No. 333-42497) pertaining to the 1990 Incentive Stock Plan, the 1995 Stock Option Plan, the 1995 Employee Stock Purchase Plan, and the 1995 Directors' Stock Option Plan of our report dated July 22, 1998, with respect to the 1998 and 1997 consolidated financial statements and schedule of Metra Biosystems, Inc. included in the Annual Report (Form 10-K) for the year ended June 30, 1998. ERNST & YOUNG LLP Palo Alto, California September 24, 1998