The present invention relates to methods for increasing the diversity ofmonoclonal antibodies produced against an antigen. The methods of theinvention utilize immunization of a murine host defective in one or moreenzymes involved in a post-translational modification of a polypeptide or amodification of a lipid, wherein said modification is exposed on a cellsurface. The invention also relates to monoclonal antibodies produced by thesemethods and which are not produced when a normal mouse is immunized with thesame antigen. The invention further relates to compositions comprising thesemonoclonal antibodies, as well as to such monoclonal antibodies bound orconjugated to a toxin, a detectable marker or to a solid support.
