EXHIBIT 99.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350 AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report of IGEN International, Inc. (the "Company") on Form 10-Q for the period ended June 30, 2002 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), each of the undersigned, in the capacities and on the dates indicated below, hereby certifies pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to his knowledge: 1. 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 operation of the Company. August 14, 2002 /s/ Samuel J. Wohlstadter ------------------------- Samuel J. Wohlstadter Chief Executive Officer August 14, 2002 /s/ George V, Migausky ---------------------- George V. Migausky Chief Financial Officer