Increased sensitivity in antigen detection during immunoblot analysis resulting from antigen enrichment via immunoprecipitation.

The sensitivity in antigen detection during immunoblot analysis is greatly increased if the antigen is first immunoprecipitated from the crude extract before electrophoresis and transfer to nitrocellulose. Not only does the method allow detection of antigens which are minor components of crude mixtures or antigens which cannot be radiolabeled, but the method also resolves problems, such as high background, which are often associated with immunoprecipitation. Also, by modifying the method, whether or not monoclonal antibodies recognize the same or different antigens and/or epitopes can be easily determined.