CDC activity of five clinically tested anti-EpCAM monoclonal antibodies. CDC was determined for three mAb concentrations. Human serum (10%) was added to cultures of KATO III gastric carcinoma cells and CDC after 45 min monitored by TDA released from lysed cells chelated with Europium and quantified by the fluorescence of the Europium-TDA chelates formed. Controls included incubation with heat-inactivated human serum, and human IgG1 and murine IgG2a isotype control antibodies. Results from triplicate determinations and standard deviations are shown.