The eighth component of human complement (C8): isolation, characterization, and hemolytic efficiency

A method was described allowing the isolation of the eighth component of complement, C8, from human serum. C8 is an immunochemically definable, heretofore unrecognized serum protein with a molecular weight of approximately 150,000 and an electrophoretic mobility of a gamma(1)-globulin. It may be obtained with 5% yield as a 5000-fold purified, physicochemically and immunochemically homogeneous protein. Under optimal experimental conditions, a few molecules of C8 were found sufficient for lysis of a cell.