Liebermann's Reaction
Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.
Summary
Liebermann's reaction is a color test for proteins based on heating a dry protein sample with hydrochloric and sulfuric acids to produce a violet color. This historical biochemical test detects the simultaneous presence of a carbohydrate group and tryptophan within the protein molecule.
Encyclopedia entry (1928–1936)
LIEBERMANN'S REACTION for proteins: upon heating (do not boil!) a dry protein with an excess of fuming hydrochloric acid or a mixture of weaker hydrochloric acid and concentrated H2S04, the liquid acquires a violet color that turns brown upon standing. Liebermann's reaction is caused by the simultaneous presence of a carbohydrate group and tryptophan in the protein molecule. Proteins that do not contain tryptophan (glutin) do not give Liebermann's reaction. The reaction only succeeds with undiluted proteins; proteins must be preliminarily isolated from solutions (coagulated by boiling).
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Cite this page
“Liebermann's Reaction.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/liebermanns-reaction/