The occurrence of shared idiotypic specificity among the goat antibodies that distinguish human hemoglobin S from A¹

Rabbits were immunized with the goat antibody population(s) that distinguishes human hemoglobin S (sickle) from A₁. After appropriate absorption these rabbit sera bind only the S specific antibody and not the antibodies that cross react with hemoglobin A₁. S specific antibody from three individual outbred goats gives reactions of complete immunologic identity in double diffusion reactions in agar with rabbit sera made specific for the antibody that distinguishes hemoglobin S from A₁. Quantitative studies of these reactions by radioimmunoassay support the notion that the idiotypic determinants from these three goats have similar antigenic reactivity.