COMPONENTS OF GUINEA PIG COMPLEMENT

Abstract

4 components of complement (C[image]) were studied, which reacted after C[image]l, C[image]4 and C[image]2 in the absence of divalent cations. The order of reaction was C[image]3c[forward arrow]C[image]3b[forward arrow]C[image]3a[forward arrow]C[image]3d. C[image]3b was strongly inhibited at 0[degree]C; C[image]3a reacted nearly as well at 0[degree]C as at 37[degree]C; and C[image]3d was intermediate. C[image]3a was very labile at 56[degree]C, C[image]3d was somewhat less so, and C[image]3b was moderately stable. C[image]3b was rapidly inactivated at low pH, C[image]3a was not. C[image]3d was the last detectable component to react before immune hemolysis begins, and may be enzymic in nature. When whole serum was absorbed with antigen-antibody complexes C[image]3c and C[image]3b were depleted but C[image]3a and C3d were not.