Detection and quantitation of proteoglycans extracted from cell culture medium and cultured cartilage slices.

Detection and quantitation of extracted proteoglycans, by staining with the dye Alcian blue on cellulose acetate followed by dissolution of the stained cellulose acetate strips in dimethyl sulfoxide containing 0.5% (v/v) sulfuric acid for absorbance measurement, is described. It is shown that, in the present system, the dye uptake by the proteoglycan is dependent only on the glycosaminoglycan content of the proteoglycan. The method is applied to the quantitation and characterization of proteoglycans and glycosaminoglycans, which have been extracted from radiolabeled bovine ankle cartilage and from mononuclear cell supernatant and which have been separated by DEAE-Sephacel column chromatography. The high sensitivity of the method allows detection of proteoglycans in 25-microliters samples of solutions containing as little as 1 microgram of glycosaminoglycan per milliliter of solution.