ADCC activity of five clinically tested anti-EpCAM monoclonal antibodies. ADCC was determined by dose response analysis as shown for 2 out of 5 human PBMC donors tested. KATO III gastric carcinoma cells were coincubated with human PBMC at an E:T ratio of 50:1 for 2.5 hours in the absence of presence of indicated mAb concentrations. Cell lysis was determined by TDA released from lysed cells chelated with Europium and quantified by the fluorescence of the Europium-TDA chelates formed. Results from triplicate determinations and standard deviations are shown.