The Reactions of Antiserum Homologous to the 4-Azophthalate Ion

Abstract

In connection with our studies on the nature of the forces operating in the combination of haptens with hapten-homologous antisera it became apparent that a study should be made of an antiserum prepared against a haptenic group containing two or more discrete negative charges, in order to determine the difference in combining power with this antibody of substances containing a single negative charge and substances containing two charges. Great specificity for the charged group has been observed for singly charged haptenic groups: thus benzenesulfonate ion and benzenearsonate ion were found not to combine with antibodies homologous to the benzoate ion group, and benzenesulfonate ion and benzoate ion were found not to combine with antibodies to the benzenearsonate ion group; but when the ions are very closely related, as are benzenephosphonate ion and benzenearsonate ion, there is appreciable cross reaction. We were interested to discover whether antibodies homologous to haptenic groups containing two charges would show greater or less specificity than was shown by these antibodies.