Tryptophan is an amino acid. Hopkins Cole test is a specific test used for the detection of tryptophan. When tryptophan is present in a solution, it gives a reddish violet ring. REAGENTS of Hopkins Cole test: Hopkins Cole Reagent: Magnesium compound of Glyoxalic acid and concentrated H2SO4. PRINCIPLE: Concentrated H2SO4 causes dehydration of tryptophan which reacts with … [Read more...]