Complement-dependent cytotoxicity in CHO-AQP4 cells produced by aquaporumab antibodies. A. Cytotoxicity was assayed 1 h incubation of cells with antibody and 2% human complement, following by readout of cytotoxicity using Alamar blue. B. Percentage cytotoxicity as a function of antibody concentration [AQP4 Ab], with antibody and complement incubations done at 27 or 37 °C (mean ± S.E.M., n=4). C. Live/dead cell imaging for experiments done as in B, with 200 ng/ml rAb-53 or affinity-matured antibody (without Fc mutations). D. EC50 values for killing, comparing with Kd for binding (from Fig. 1C) (mean ± S.E.M., n=4).