EXHIBIT 21.1 SUBSIDIARIES OF REGISTRANT Genus Subsidiary Corporation, a California corporation. Genus Ionex Corporation, a Massachusetts corporation. Ionex/HEI Corporation, a Massachusetts corporation. Genus Europa GmbH, a German company. Genus Europa Ltd., a British company. Genus Europa SARL, a French company. Genus Europa S.r.l., an Italian company. Genus KK, a Japanese company. Genus Korea, Ltd., a Korean company. Page 45