Exhibit 32.2

Certification of Periodic Report

I, Christine A. Tsingos, Chief Financial Officer of Bio-Rad Laboratories, Inc. (the “Company”), certify, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, 18 U.S.C. Section 1350, that:

(1)

the Quarterly Report on Form 10-Q of the Company for the quarterly period ended June 30, 2005 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2)

the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date:	August 8, 2005	/s/ Christine A. Tsingos
		Christine A. Tsingos
		Vice President, Chief Financial Officer