Liebermann-Burchard reaction for cholesterin

Cholesterin, when di olved in chloroform, to which a small amount of acetic an hydrid has first been added and then concentrated sulphuric acid drop by drop, yields a red color changing to blue and finally to green. [C. Liebermann, ical chemists.]H. Burchard, German biolog- Liebermann's reaction for proteins. Consists of heating a protein, which has been washed with alcohol and ether, with concentrated hydrochloric acid, when a violet color is produced. This color, as Cole has shown, is due to the presence of glyoxylic acid in the ether, which reacts with the tryptophans, yielding this violet color with hydrochloric acid. [Leo von Szentlbrincz Liebermann, Hungarian physician, born 1852.]