Radioimmunocytochemistry-a novel immunocytochemical principle.

Currently available immunocytochemical techniques rely on the detection of the antibody by means of direct labeling or indirect immunologic procedures. To increase immunocyto-chemical specificity a new radioimmunocytochemical method has been developed. In the radioimmunocytochemical method radiolabeled antigen is incubated with surplus amount of antibody. In this way only one combining site of the antibody will bind the labeled antigen, leaving the other site free to react with tissue-bound antigen. The site of reaction with tissue antigen is revealed by autoradiography. The radioimmunocytochemical method is specific and sensitive and can be combined with conventional staining methods or with immunoperoxidase techniques. It may also be useful for ultrastructural and quantitative immunocytochemistry.