A method for enhancing production of antibodies through immunization with insolubilized immune complexes is disclosed. Purified antigen or heterogeneous antigen mixtures may be combined with polyclonal or monoclonal antibody and the resultant complex bound to an insolubilized matrix to form insolubilized immune complexes. Methods for improving the immunogenicity of a soluble antigen and for producing monoclonal anti-iodiotypic antibodies are also disclosed. Monoclonal antibodies that are specific for a distinct, as yet unrecognized epitope may be produced by another disclosed method . Insolubilized immune complexes, comprising antigen and antibody that is ether directly linked to Sepharose.RTM. or absorbed onto insolubilized protein A, and immunosorbents, comprising antibody absorbed onto insolubilized protein A, are also disclosed.