Figure 3. Competition of the ADCC reaction with excess human IgG. ⁵¹Cr labeled SKBR-3 cells (T) were incubated with effector cells (E) at an E:T ratio of 30:1 for 16 h. Specific lysis (%) induced by 400 ng/ml of MB 314 or MB 311, respectively, in the presence or absence of excess of human IgG is shown. Horizontal line indicates lysis of target cells by effector cells without antibody. Mean and SD of triplicates are shown.