The purification of azoprotein antibodies by the dissociation of specific precipitates

Abstract

Specific precipitates containing 10-30% of azoprotein and 70-90% of antibody are, on the addition of acids, converted into non-specific azo-protein-globulin precipitates, containing <50% of antibody. About 50-80% of the antibody is thus released from the precipitate and passes into the acid soln. HC1 or phosphoric acid, containing 5% of NaCl, was used for the dissociation of the precipitates. Antibodies to anthranilic, arsanilic and sulfanilic acids and p-aminobenzylamine-azo-globulins were purified by this method. About 40-70% of the dissolved protein was active antibody, precipitable by the homologous antigen. A repetition of the same procedure furnished antibody prepns. of a high degree of purity containing at least 90% of precipitable antibody.