Studies of Anti-Horse Crystalbumin Sera

Abstract

Summary The data presented in this paper concern the reactions of 44 anti-horse crystalbumin sera with human serum albumin and with bovine serum albumin. The antisera were obtained from 17 rabbits; 17 antisera were obtained after 2, 14 after 3 and 13 after 4 courses of injections of horse serum crystalbumin. In ring tests it was found that 1:128 and 1:512 dilutions of 2% solutions of heterologous albumins provided more sensitive tests for the presence of heterologous antibody than 1:2 and 1:8 dilutions. Ring tests and optimal proportions titrations on antisera obtained from an individual rabbit after successive courses of injections did not indicate a consistent increase in the concentration of antibody which reacted with a heterologous antigen. In a graph which represents the relationship between the logarithms of the optimal ratios and of the flocculation times of 44 anti-horse crystalbumin sera with homologous antigen, the points were considered to lie on a straight line (3). In an analogous graph showing the reactions of 23 of these anti-horse crystalbumin sera with human albumin, the points lie within a broad oblique band except for that representing one antiserum. Differences in the intensities of the homologous and heterologous reactions of the antisera cannot be explained solely by differences in their content of an antibody of uniform specificity: whereas some antisera reacted more rapidly with human than with bovine albumin others reacted more rapidly with bovine than with human albumin. The experiments recorded suggest the existence of antibodies of different specificity in the antisera.