A STABLE HISTOCHEMICAL GMELIN REACTION OF BILE PIGMENTS WITH DRY BROMINE-CARBON TETRACHLORIDE SOLUTION

Treatment of bile pigments of tissue sections with dry solutions of bromine in carbon tetrachloride (0.5%, v/v) for intervals of 10-90 min produces a range of colors from very dark violet or red purple through lighter shades to pale rose pink or yellowish pink. Preparations may be mounted in xylene cellulose caprate and colors remain demonstrable for some weeks, although with some fading. The reaction is regarded chemically as equivalent to the traditional Gmelin reaction and offers an additional identification reaction for these pigments. Some samples of hematoidin also react, but repeated application of the test may be needed.