The Development of Antibodies to Penicillin in Rabbits

A method for the production of antibodies specifically directed against penicillin is described. The inability of this antibody to significantly reduce the antibiotic activity of penicillin is noted. Evidence to show the variability of specificities of various sera, some directed for the most part against the side chain, others against the nucleus is presented. Studies on serum fractions separated electrophorectically indicate that the antibody migrates in the fast gamma-globulin and beta-globulin fractions and requires dextran or albumin to effect agglutination. The inability of penicilloic acid, an hydrolysis product of penicillin to provoke antibody formation despite its ability to inhibit the antibody is shown and the implications of this observations are discussed.