Recent advances in the detection and characterization of specific antibody-forming cells in tissue sections.

A new general approach has been developed for the detection of one or more different specific antibody producing cells and the simultaneous determination of their Ig isotype in tissue sections, after immunization of animals. Specificity of intracellular antibodies is demonstrated after incubation of the sections with an antigen-enzyme conjugate and the isotype of the antibodies is determined using an anti-immunoglobulin (Fc chain-specific)-enzyme conjugate followed by histochemical revelation of the two different enzymes. The principles of the method, the required antigen- and antibody-enzyme conjugates and their application in single, double or triple staining studies are reviewed. The method allows the detection of specific antibody-forming cells against protein antigens as well as against haptens. By means of haptens such as trinitrophenyl (TNP), immune responses against thymus dependent, thymus independent, and particulate antigens can be studied. In a limited number of cases the method can also be used to study the localization of antigen-antibody complexes.