[Acid mucopolysaccharide detection on ultra-thin sections by alcian blue in dental tissues embedded in Epon]

Ultra-thin sections of dental tissues, fixed in glutaraldehyde and osmium tetroxide, embedded without previous demineralization in Epon, were contrasted the grids with an alcian blue solution after previous oxidation periodic acid or hydrogen peroxide. Correlations with histochemical results obtained with the optical microscope, other results obtained with ruthenium red and phosphotungstic acid and controls made after enzymatic digestion with chondroitinase AC suggest that this technique is specific for the detection of acid mucopolysaccharides in those calcified tissues studied.