DEMONSTRATION OF PEROXIDASE ACTIVITY IN TISSUE SECTIONS

By using an improved benzidine technique, peroxidase activity can be demonstrated in various locations in mammalian tissues. A relatively formalin resistant enzyme is found in hemoglobin and is also associated with mitochondria of striated muscle and heart. A somewhat less formalin resistant peroxidase occurs in the granules of myeloid and mast cells. A relatively formalin sensitive peroxidase is present in a number of additional locations, e.g. the acinar cells in thyroid and salivary gland, the medulla of the kidney, in hair follicles of the guinea pig skin and Kupffer cells of the liver.