NURSING ANM AND GNM

Detailed explanation-1: -The tryptophan indole ring reacts with glyoxylic acid in the presence of sulphuric acid (VI) to form a product of a red-violet colour.

Detailed explanation-2: -The Hopkins-Cole reaction, also known as the glyoxylic acid reaction, is a chemical test used for detecting the presence of tryptophan in proteins. A protein solution is mixed with Hopkins Cole reagent, which consists of glyoxylic acid. Concentrated sulfuric acid is slowly added to form two layers.

Detailed explanation-3: -Hopkin’s Cole test is a specific test used for the detection of indole ring and thus, tryptophan in proteins. The test is also termed as ‘glyoxylic acid test’ as the reagent contains glyoxylic acid.