Comparison of heterogeneities of antitrinitrophenyl antibodies in strains of mice immunized by various methods.

Heterogeneity of antibodies directed against the trinitrophenyl (TNP) determinant in immunized mice was analyzed by investigating the band groups of antibodies formed by thin layer isoelectric focusing of serum. The degree of heterogeneity in C57BL/6 mice was markedly higher than that in CBA mice under the following conditions of immunization: immunization with TNP conjugated with bovine gamma-globulin or ovalbumin, interchange of these carrier proteins at the first and second injections, change of epitope density of the antigens, replacement of the hapten by dinitrophenyl group on the antigen for the secondary stimulation, and change of intervals of these injections from 15 days to five months. The degree of heterogeneity within a strain also varied with these immunizing conditions. Furthermore, the heterogeneity in C57BL/6 mice of any immunization group was greater than that in CBA mice in any group. This was also true when the heterogeneity was examined with the immune sera diluted to the same titer. These results indicate that the number of predominant clones of cells producing anti-TNP antibody after immunization is larger in C57BL/6 than in CBA mice.