EXHIBIT 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of our report dated January 15, 1999, except as to Note 11, which is as of January 27, 1999, relating to the financial statements and financial statement schedule, which appear in LJL BioSystems, Inc.'s Annual Report on Form 10-K for the year ended December 31, 1998. We also consent to the reference to us under the heading "Experts" in such Registration Statement. PRICEWATERHOUSECOOPERS LLP San Jose, California June 29, 1999