Oxidation of tissue polysaccharides by periodic acid in dimethyl sulfoxide and its anhydrous and aqueous mixtures.

Periodic acid (1% w/v) solvated by anhydrous dimethyl sulfoxide (DMSO) readily induced a strong Schiff reaction in a variety of structures containing polysaccharides, but not glycogen. With the increasing amounts of water added to DMSO, glycogen was also oxidized, while the selective localization of other polysaccharides remained unimpaired. Periodate, solvated in the anhydrous acetic acid-DMSO mixture, rapidly induced concomitant oxidation of nucin and glycogen-containing structures. Sodium bisulfite addition derivatives of carbonyls, induced by periodate oxidation in DMSO, were stained meta- and orthochromatically with toluidine blue at controlled pH. Certain metachromatic tissue components were strongly birefringent in polarized light in contrast to the identical structures oxidized by aqueous periodate. Marked differences in staining reactions elicited in identical structures by periodate in DMSO as compared with aqueous periodate suggest that DMSO-periodate method considerably enhances the range of histochemical oxidations by periodate.