The specific cytochemical demonstration in the electron microscope of periodate-reactive mucosubstances and polysaccharides containing vic-glycol groups

Summary A technique is described for the localization in the electron microscope of periodate-reactive mucosubstances and polysaccharides containing vic-glycol groups. In this technique the sugar residues are oxidized by periodic acid and the resulting aldehydes condensed with pentafluorophenylhydrazine under specified conditions. Further increase in specific electron density is achieved by treating the hydrazone end-product with ammonium sulphide followed by osmium tetroxide to form an osmium black.The technique has been applied to liver and small intestine cells in which glycogen, sialomucins and sulphated mucosubstances reacted especially strongly. A marked positive reaction has also been obtained from the interstitial cell matrix and from the Golgi apparatus and multivesicular bodies of the intestinal epithelial cells.The reaction can be prevented by the omission of the periodate oxidation and, if due to glycogen, by prior treatment with diastase.