Molischs test is a sensitive chemical test used to detect the presence of carbohydrates in a given analyte. This test is named after Austrian botanist Hans Molisch, who discovered it. The test solution is combined with a small amount of Molischs reagent (α-naphthol dissolved in ethanol) in a test tube. After mixing, a small amount of concentrated sulfuric acid is slowly added down the sides of the sloping test-tube, without mixing, to form a layer. A positive reaction is indicated by the appearance of a purple-red ring at the interface between the acid and test layers. The principle of Molischs test is based on the dehydration of carbohydrates by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with α-naphthol to form a purple-colored product. The test is commonly used to detect all carbohydrates larger than tetroses. The Molisch test is used to determine the presence of carbohydrates or sugars in the substance. The presence of some glycoproteins and nucleic acids can also be determined by Molischs test. The limitations of the Molisch test include the lack of specificity for carbohydrates and the possibility of false positives due to the presence of other reducing substances.