A ruthenium-103 red dot blot assay specific for nanogram quantities of sulfated glycosaminoglycans

Ruthenium-103 red has been used previously to detect nanogram quantities of glycosaminoglycans after they have been separated by electrophoresis on cellulose diacetate. We have applied the critical electrolyte principle to the binding of this dye to polyanions. This eliminates interaction with nucleic acids and hyaluronan. After samples are digested with chondroitinase ABC the method allows the measurement of chondroitin sulfates and heparan sulfates at the 2-ng level in dot blots of tissue extracts.