Molisch's test

Molisch the sample ( or by Molisch reaction ) is a general carbohydrate detection. It goes back to the Austrian botanist Hans Molisch.

Implementation and response

A dilute ribose is mixed with Molisch 's reagent ( solution of α -naphthol in ethanol). The reaction mixture is overlaid with concentrated sulfuric acid. A violet ring is formed at the interface.

Under the action of a strong acid, such as concentrated sulfuric acid, 5-hydroxymethylfurfural is from the pentoses and hexoses by intramolecular dehydration and furfural. This condensed with α -naphthol to form a violet dye. This dye is formed by all compounds that contain carbohydrates, so for example, nucleic acids and glycoproteins.