Use of the dot-blot immunogold assay to identify a proliferative antigen in the initial cells of a wheat stem meristem

We have devised a protocol for the isolation and identification of a prolif erative antigen of the initial cells of wheat stem meristems (termed PAI). We have carried out a variety of immunochemical and immunocytochemical meth ods, using colloidal gold (CG) complexed with monospecific antibodies to PA I as the marker for the detection of PAI. We have been able to determine th e effectiveness of immunoaffinity chromatography in isolating PAI from plan t tissues and have shown the advantages of CG over enzyme labels for identi fication of the antigen. Finally, we have obtained a purified preparation o f PAI and have determined its molecular mass (similar to 83 kDa).