Preparation of antisera to bovine immunoglobulin classes by immunization with agar-gel precipitates.

Antisera to bovine IgM and IgA were developed by immunizing rabbits with specific agar-gel immune-precipitates. By precipitation with a polyvalent anti-immunoglobulin serum the immunoglobulin classes were isolated from solutions which contained IgM (G-200 gel-filtration fractions) or IgA (lacrimal fluid) as the only or at least predominant immunoglobulin. Antibodies developed against shared antigenic determinants (light polypeptide chains) and non-immunoglobulin proteins were easily removed using selected absorptive materials. Attempts to produce antisera exclusively reactive with either IgG slow or IgG fast were unsuccessful, presumably due to slight antigenicity of subclass-specific determinants.