Ferric chloride test in PKU gives: (A) Green, (B) Red, (C) Yellow, (D) Blue
Answer is A. Urine of the patient contains phenylketones about 500- 3000 mg/day . This could be detected by adding a drop of ferric chloride to the urine . A transient blue - green color is a positive test. But this is a less reliable test. Ref : DM.VASUDEVAN.TEXTBOOK ; SEVENTH EDITION ; PAGE NO : 237.