Automation of 1,9-dimethylmethylene blue dye-binding assay for sulfated glycosaminoglycans with application to cartilage microcultures.

The 1,9-dimethylmethylene blue dye-binding assay for sulfated glycosaminoglycans has been modified and adapted for use on a Technicon autoanalyzer. The assay was linear for chondroitin sulfate from 2.5 to 500 micrograms/ml and used only 2.5 microliters sample. Interference by salts and solvents commonly used in proteoglycan research was minimal and could be compensated for by using standards in the appropriate solvent. High concentrations of albumin and serum interfered strongly but most of the inhibition could be overcome by papain digestion.