Heterogeneity of cross-reactivity of mouse anti-benzylpenicilloyl antibodies against cephalothin haptens or polymers.

The cross-reactivity of mouse anti-benzylpenicilloyl antibodies against cephalothin-haptens and cephalothin-polymers was divergent depending on the source and isotype of antibodies and the methods to raise them. High cross-reactivity nearly equal to the reactivity to homologous haptens and polymers was obtained only with the IgE antibody of C57BL/6J mouse raised shortly after an immunizing injection of the emulsion containing Freund's complete adjuvant and benzylpenicilloyl-bovine gamma-globulin conjugate. With the other antibody preparations, cross-reactivity was moderate to negligible.