A Quantitative Precipitin Study of Porcine Fibrinogen Employing Paired Labels

Abstract

Globulins from single bleedings of individual rabbits were used to delineate the quantitative precipitin reaction of porcine fibrinogen and its homologous antibody. The use of paired radioactive labels in both antigen and antibody, as an aid in studying the quantitative precipitin reaction, was established. Porcine fibrinogen prepared by different methods yielded antigens with differing immunochemical properties. The effective antigenic valence of one preparation was 27; of another, over 50. Precipitin titrations with one resulted in classically linear Heidelberger plots; with another, in curvilinear departures from the ideal in antibody excess regions.