The preparation and characterization of a thymic independent antigen: ϵ-dinitrophenyl-L-lysine-ficoll

Abstract The preparation of a hapten-polysaccharide conjugate, ϵ-dinitrophenyl- L -lysine-Ficoll, is described. Conditions yielding different substitution ratios were studied. Ultracentrifuge and gel filtration studies have shown a very broad range size heterogeneity. The conjugates were shown to elicit both immediate and delayed skin reaction in guinea pigs previously immunized with dinitrophenylated keyhole limpet hemocyanin. The presence of antibody forming cells in the spleens of mice immunized with the conjugates was established by the demonstration of plaque-forming cells when assayed with trinitrophenylated sheep red blood cells. The immunogenicity, as shown by the plaque-forming cell response, was shown to be markedly dependent on the size of the conjugates.