I. FeC13 test: →
i. 10% FeCl3 mixed with fresh urine →Emerald green colour → detect phenylpyruvic acid in urine (led in phenyl ketonuria).
ii. Gerhardt’s test for Aceto-acetic acid by Adding 5%ferric chloride (detect ketone bodies) (iii) In maple syrup urine disease FeCl3→gives navy Blue colour in urine.
II. Guthrie’s test →for Diagnosis of phenylketonuria, it is a microbiological test based on the principle that phenylalanine is necessary for growth of Bacillus subtilis. (Not, based on phenyl pyruvic acid)