Simple spectrophotometric quantification of urinary excretion of glycosaminoglycan sulfates.
We describe a simple, rapid, precise, and sensitive spectrophotometric method for measuring urinary glycosaminoglycan (GAG) sulfate excretion. The GAG sulfates are precipitated with cetylpyridinium chloride, resuspended in water, and mixed with the basic dye 1,9-dimethylmethylene blue to produce a complex with the polyanionic molecule of sulfated GAGs. Absorbance is read at 535 nm. The standard curve for reaction was linear up to 12 micrograms of the different GAGs: dermatan sulfate, heparan sulfate, keratan sulfate, chondroitin 4-sulfate, and chondroitin 6-sulfate. Within- and between-run precision (CV), measured at three different GAG concentrations (normal and pathological), varied from 1.6% to 2.5% and from 1.8% to 4.5%, respectively. Analytical recovery ranged from 71% to 107%. Urinary GAG excretion, measured by this procedure, correlates (r = 0.837; p less than 0.001) with the values obtained with the borate-carbazole reaction (Anal Biochem 1962;4:330-4).
D000293:Adolescent; D000328:Adult; D001888:Boric Acids; D002227:Carbazoles; D002648:Child; D002675:Child, Preschool; D005260:Female; D006025:Glycosaminoglycans / Q000652:urine*; D006801:Humans; D007223:Infant; D008297:Male; D008751:Methylene Blue / Q000031:analogs & derivatives; D009085:Mucopolysaccharidosis IV / Q000652:urine; D013053:Spectrophotometry; D013223:Statistics as Topic
D001888:Boric Acids; D002227:Carbazoles; D006025:Glycosaminoglycans; C041514:carbazole; C013786:A73025; C032688:boric acid; D008751:Methylene Blue; C016401:1,9-dimethylmethylene blue