A direct spectrophotometric microassay for sulphated glycosaminoglycans in cartilage cultures

Abstract

The authors describe a rapid spectrophotometric procedure for the estimation of sulfated glycosaminoglycans in cartilage cultures. Papain digestion of tissue or culture medium provides glycosaminoglycans in solution for assay; an aliquot of the digest is mixed with the dye 1, 9-dimethylmethylene blue. The assay is based on the metachromatic shift in absorption maximum that occurs when the dye is complexed with sulfated glycosaminoglycans. The reagent is stable, and the method is largely free from interference, is sensitive to less than 1 ìg (4 ìg/ml) of chondroitin sulfate, and provides a more straightforward alternative to the older methods for glycosaminoglycan determinations