Yoshihiko Horiuchi

Effect of antigenic valency on precipitin reactions of anti hapten antibodies

Abstract Rabbit anti-benzylpenicilloyl antibodies of the IgG class were analysed by quantitative precipitin reactions with benzylpenicilloyl antigens having different number of antigenic determinants. The amount of precipitated antibody of a given serum pool increased along with the number of the determinant groups of the antigen. A relationship between the maximal amount of precipitable antibody and the valency of the antigen was given as a cummulative function of antibody populations which showed normal distribution. The precipitability of antibodies was affected by the duration of immunization until the tested serum was bled; i.e., early antibodies were less precipitated with antigens of small valency when compared with late antibodies. Non-precipating antibody was found to form soluble antigen-antibody complex even at a point of maximum antibody precipitation.