Binding of DCH and variants to Ep-CAM. The human adenocarcinoma cell line Kato III was incubated with various amounts of recombinant fusion proteins. Binding was analyzed by flow cytometry using an anti-penta-His mouse IgG1 and FITC-conjugated goat anti-mouse F(ab)₂ detection system. The mean fluorescence intensity (MFI) of cells from duplicate determinations is plotted against the concentration of DCH and variants.