Immunochemical specificity of a benzidine technique proposed to catalases histochemical detection.

As an attempt to test the specificity of an histochemical technique proposed to detect catalases, an investigation was carried out by immunochemical techniques. Purified catalases were used after analysed immunochemically by double immune diffusion test and immunoelectrophoretic technique. These pure catalases induced, after injecting into guinea-pigs, anti-serums that react specifically with catalase and does not give any cross reaction with peroxidases and haemic iron containing compounds. By the direct and indirect immuno-fluorescence techniques it was shown an intense catalase reactivity inside the cytoplasm of adrenal cortex and hepatic cells, that appears as a granular pattern. These results are very similar to those provided by the histochemical technique, either concerning to the reactive cells or to the granular pattern of the positive reaction. In such instances, the immunochemical results suggest the specificity of the histochemical reaction. This specificity is confirmed by the previous treatment of tissue sections by catalases anti-serum. After this treatment either the immunochemical or the histochemical technique to detect catalases provide negative results on cells that before the treatment were strongly reactive.