Microwave superheating enhances immunocytochemistry in the freshly frozen rat brain

The goal of this study was to evaluate the effects of microwave irradiation on immunocytochemical staining in freshly frozen rat brain tissue using an antibody previously shown to successfully stain only formalin-fixed materials. GFAP immunoreactivity was markedly increased in sections exposed to microwave heating when compared with control tissue. Uniform staining enhancement was mainly a result of increased numbers of immunoreactive soma and large astrocytic processes. The integrity of the tissue was not affected by this treatment. Other antibodies need to be tested with this method, but our results suggest that microwave irradiation is useful for rapid antigen retrieval in freshly frozen central nervous system tissue.