Electron histochemistry of mucosubstances in normal human rectal epithelium

The electron microscopic histochemistry of mucosubstances in sigmoidoscopically and microscopically normal rectal biopsies was studied using techniques currently available. The deposition of Alcian Blue and Ruthenium Red and the distribution of Concanavalin A receptors were limited to the epithelial cell borders. Mucosubstances in the fuzzy coat, Golgi apparatus, lysosomes and secretory vesicles were demonstrated by the periodic acid-chromic acid oxidation methods. Glycogen was demonstrated in the epithelium by periodate oxidation methods and the complex cyanide technique. There was little difference in the distribution of mucosubstances in the epithelial cells at any level of the crypts. Phosphotungstic acid staining under controlled conditions gave a similar distribution of mucosubstances to those revealed by the oxidation techniques.