On the application of the unlabelled peroxidase-antiperoxidase method to the investigations of the nervous tissue.

The unlabelled peroxidase-antiperoxidase (PAP) method was applied to the nervous tissue, to investigate whether there are cells which show the localisation of immunoglobulins of IgG, IgA and IgM type. The experiments performed have shown no positive reaction with the PAP method in normal brain tissue. In tumor tissue some cells, rich in cytoplasm of gemistocyte-like appearance or reactive astrocytes stained positively with the PAP method. The reliablility and specificity of the reaction is discussed.