The Lipid and Protein Staining Properties of Sudan II, III and IV and Their Components

Abstract
Saturated solutions of commercial Sudan II, III and IV in 60% ethanol were found to stain heat-coagulated fat-free purified human serum albumin and defatted whole serum. The protein staining components were isolated and identified by means of paper chromatography on mineral oil-impregnated filter paper with 95% ethanol as the developing agent. The brownish and yellowish fractions which migrated rapidly in this system stained proteins well, whereas the red, pink and orange fractions, which migrated slowly, stained lipids only. The solubility and staining power of the slowly migrating lipid coloring fractions remained satisfactory in absence of the rapidly moving protein staining fractions.