Abstract
1. The present study was undertaken to obtain evidence of antigenic binding of aminopyrine and its metabolites.
2. A metabolic intermediate of aminopyrine, 3-formyl-2-methyl-4-dimethyl-amino-1-phenyl-3-pyrazolin-5-one (AM-CHO) is conjugated to a considerable extent with bovine γ-globulin (BGG) at alkaline pH.
3. The AM-CHO-BGG conjugate with Freund's complete adjuvant injected intradermally into three male rabbits, gave antisera that contained antibodies to AM-CHO hapten and to native carrier protein, BGG, as indicated by the tanned red cell haemagglutination test.