Differences in the immune response of rabbits to p-aminobenzoic acid and sulphanilic acid,conjugated with BGG

1) After immunization of rabbits with two structurally similar haptenes—p-aminobenzoic acid and sulphanilic acid—conjugated with the same BGG molecule, three groups of animals can be differentiated, according to the type of antibody response; a) animals forming antibodies well against both haptenes, b) animals forming no, or low titres of antibodies against both haptenes and c) animals forming antibodies well against one of the given haptenes, but not (or only in very low titres) against the other. 2) Hybridization experiments showed that the capability or incapability to synthesize antibodies against a given haptene depends on the genotypical constitution of the individual concerned.