[Comparative studies of the specificity of idiotypic guinea pig and carp antisera]

The specificity of guinea-pig- and carp-anti-idiotypic antisera were compared by using the radioimmunoassay and the passive hemagglutination inhibition test. Guinea-pigs and carps were immunized with the IgA/k mouse myeloma protein S117 which has binding activity to the hapten N-acetylglucosamine. the resulting antisera were idiotypically specified by absorption and the activity was determined by the binding of the radiolabeled idiotype S117. The binding curves of guinea pig and carp anti-idiotypic antisera are very similar. The idiotype-anti-idiotype reaction could be partially inhibited by the specific hapten N-acetylglucosamine but not by N-acetylgalactosamine. Both antisera, guinea pig and carp, respectively, are different in respect to the immunoglobulin class of anti-idiotypic antibodies which react with the idiotype S117. In the case of the guinea pig antisera the anti-idiotypic antibodies are mainly of the IgG-type whereas the anti-idiotypic antibodies of carp are exclusively of IgM-type. This important difference is discussed.