Exhibit 21 Subsidiaries of Registrant EXHIBIT 21 LIST OF SUBSIDIARY COMPANIES Unilabs Group Limited (BVI) - 100% Unilabs SA (Swiss) - 61% Unilabs Group (UK) - 100% Unilabs Clinical Pathology Limited - 100% Farrer-Brown Histopathology Limited (UK) - 100% United Trust Laboratories Limited - 100% Unilabs Medizin. Labor. AG (Swiss) - 100% Laboratorie Ritton SA (Swiss) - 100% Enzym-Labor Dr. H. Weber AG (Swiss) - 100% Diagnostica, Lab. AG (Swiss) - 100% SQ-Lab Aerztelabor AG (Swiss) - 100% Medizin. Labor Baden AG (Swiss) - 100% Medizin.Labor Dr. H.R. Ebersold AG (Swiss) - 100% Laboratoire Riotton SR SA (Swiss) - 100% Vivagen Diagnostics AG (Swiss) - 100% Biomedical SA (Swiss) - 100% MS Chimie SA (Swiss) - 100% Praxilab Gem. Prakt. Aerzte AG (Swiss) - 65% Pathologie-Labor Brunnhof AG (Swiss) - 100% Instituto Medico Di Torino SpA (Italy) - 100% Medil Srl (Italy) - 50% United Laboratories Espana SA (Spain) - 98% Unilabs Management Company Limited (Gibraltar) - 100% Unilabs International Limited (BVI) Unimed Laboratories (Russia) - 50% Swisslab N.V. (Netherlands Antilles) - 61.5% Swisslab B.V. (Netherlands) - 61.5% Buyuk Swisslab Laboratuari (Turkey) - 43.1% Uni Clinical Laboratories UCL Engineering SA (Swiss) (Dormant) - 100% Global Unilabs Clinical Trials Ltd. (BVI) - 100% Unilabs Clinical Trials International, Ltd. (US) - 70% Unilabs Clinical Trials Ltd. (UK) - 100% UCT Software SA (Swiss) - 100% NDA Clinical Trial Services Inc. (US) - 100%