| Abstract: | The sera of intact and immune animals contain factors capable of inhibiting the interaction of antibodies with the homologous antigen. These agglutination inhibiting (AI) factors not only block the antigen, thus competing with antibodies, but may induce the dissociation of the antigen-antibody complex. Heating of antisera at 60-63 degrees C leads to an increase in the activity of AI factors. The phenomenon of "prozone" in the agglutination test appears to be explained by the presence of AI factors in sera. |
