Effect of complementarity determining region exchange in the light chains. Cardiolipin binding of IgG in COS-7 cell supernatants containing wild-type heavy chains expressed with wild-type or hybrid light chain constructs. (a) Light chains expressed with IS4 variable heavy chainregion (VH). (b) Light chains expressed with B3VH. Presented as concentration of IgG in the supernatant versus optical density (OD) at 405 nm in the anti-cardiolipin ELISA.