Contrasty Staining And Quantitative Determination Of Mucopolysaccharides On Filter Paper By Means Of Colloidal Iron

Abstract

The contrast between the Prussian blue color of the mucopolysaccharide spots and paper background was increased by differentiation of the paper strips (dyed in acid colloidal iron solution made up in 60% ethanol) with thioglycolic acid. Thus the trivalent iron bound to the paper background was reduced but that adsorbed by the mucopolysaccharides was precipitated as ferric ammonium thioglycolate. This procedure was found to stain equally well acid (including sulfated) and neutral mucopolysaccharides, even though these varieties exhibited different staining properties by the periodic acid-Schiff and toluidine blue dyeing procedures. Staining of different depolymerization products of hyaluronate was little influenced by their chain lengths. Quantitative determination of the mucopolysaccharide content of the spots was performed by elution of ferrocyanide with hot sodium hydroxide and measuring of the Prussian blue color of the extracts, developed on acidification and addition of FeCl₃.