“…A technique for immunoelectrophoresis with fluorescein isothiocyanatelabeled antigen and antibodies has been described (486). Radioisotopes from tagged protein fractions in polyacrylamide gel can be measured following combustion of the gel (843) or after dissolving it in ammonia (230,1218) or hydrogen peroxide (758,1281) ; densitometry of autoradiographs from intact electrophoregrams also gives satisfactory results (533,778). Detection and quantitation of proteins with antisera can be accomplished economically on cellulose acetate membranes (1 11, 715) or after microdisk electrophoresis in polyacrylamide gel (924).…”