Serological differentiation of steric isomers

Abstract

The tests presented in Tables I, II, and III show that only in the higher concentration cross reactions do take place, and that there is definite specificity of the two sorts of immune sera for the homologous antigens. Thus it is easy to differentiate the l- and d-antigens in dilutions 1 : 100 and upwards. The occurrence of cross reactions can readily be ascribed to the fact that the l- and d-acids present in the two antigens are identical in every respect but the position of the groups connected with the asymetric carbon atom. The/-antigen reacts with both sorts of immune sera as could be expected since it must consist of a mixture of equal parts of l- and d-antigen. The reactions of the/-antigen appear to be only slightly weaker than those of the homologous ones owing to the fact that the intensity of the reactions diminishes but slowly with increasing dilution of the antigens. It is also to be considered that small differences cannot be judged very accurately. © 1928, Rockefeller University Press., All rights reserved.