Automated immunoprecipitin technique for analysis of the third component of complement (C'3) in human serum.

An automated continuous-flow procedure has been developed for measuring C'3 in human serum, by reaction with specific antiserum. The procedure is standardized with pooled human serum, appropriate dilutions of which had previously been measured for C'3 by a reference method. C'3 values obtained by this new automated procedure correlate with values obtained by radial immunodiffusion. The precision (CV) of this method is 1.65%.