Comparisons of antibody-dependent cellular cytotoxicity and surface plasmon resonance analysis of binding to mouse Fcγ receptors. A, Antibody-dependent cellular cytotoxicity of GD2-BsAb and its Fc mutants against GD2+ IMR-32 cells. Effector to target ratio was 20:1. B, Antibody-dependent cellular cytotoxicity of HER2-BsAb and its Fc mutants against HER2+ AU565 Cells. Effector to target ratio was 20:1. Binding kinetics of BsAb and Fc mutants to mouse FcγRI (C, GD2-bind series, and D, HER2-binding series) and FcγRIV (E, GD2-bind series, and F, HER2-binding series). Protein binding to the SPR chip surface was measured in resonance units (RU). The results shown are representative results from at least three independent repeats.