Use of phast contrast microscopy of semithin epoxy sections in histochemistry

A number of histochemical staining methods can be applied to semithin (1-2 mum) Epon sections either unmodified or after slight modification of the original method. While only the histochemically stained specific component is visible in bright field illumination, phase contrast microscopical study of the same field of view shows also the histological and cytological details of the specimen and thus allows exact localization of the specific component in the tissue. Applications will be found in several areas in histochemistry. Practical examples are given for demonstration of periodic acid-SCHIFF-reactive mucosubstances, exogenous perioxidase, and acid phosphatase activity.