SPECTROCOLORIMETRIC ASSAY FOR THE 3 TYPES OF GASTROINTESTINAL MUCINS USING HISTOCHEMICAL STAINS

A method, transposed from the mucin histochemical stainings, was propo sed to evaluate neutral, acidic and sulphated mucins by spectrocolorim etry. Stainings used were periodic acid/Schiff (PAS), Alcian blue (AB) pH 2.5, and Alcian blue (AB) pH 0.5. Mucin samples were extracted fro m mucosal scrapings, from intestinal contents of germ-free rats or fro m commercial pig gastric mucin. A mucin-enriched fraction was obtained and lyophilised and the protein content was determined. Each mucin ty pe was spectrophotometrically analysed after staining and precipitatio n by slightly modified Carnoy fixative. The histochemical stainings us ed here, after modification by Carnoy fixative treatment, were, as sho wn by electrophoretic controls, specific for mucin types contained in these mucins without protein contaminant interference.