1 EXHIBIT 23.1 CERUS CORPORATION CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement on Form S-8 No. 333-27097 pertaining to the 1996 Equity Incentive Plan and Employee Stock Purchase Plan of Cerus Corporation of our report dated January 27, 1998, except for Note 2 as to which the date is March 6, 1998, with respect to the financial statements of Cerus Corporation included in the Annual Report (Form 10-K) for the year ended December 31, 1997. Ernst & Young LLP Walnut Creek, California March 6, 1998