<prompt> Which of the following test is done to detect the presence of urobilinogen?Guthrie testFouchets testEhrlichs testAlcian blue spot test  <response>: Ehrlichs aldehyde test: Ehlichs aldehyde reagent consists of para dimethyl amino benzaldehyde in acid solution. Equal volumes of urine and Ehrlichs reagent are mixed. Formation of pink colour indicates the presence of urobilinogen. Other Options:- Test Detects Guthrie test Screening of phenylketonuria Fouchets test bile pigments Bilirubin in urine Alcian blue spot test mucopolysaccharides in urine Additional information: Watson-Schwaz testis a qualitative screening test for the detection and differentiation of urobilinogen and porphobilinogen. Step 1: Urine Ehrlich reagent Sodium acetate - Pink or red colour - Positive test - Urobilinogen or Porphobilinogen present. Step 2:Above test solution Chloroform Step 3:PinkRed layer Butanol Note:If the pink color develops in the first step, then continue fuher. In the second step, if the colour develops in the aqueous layer, then proceed with the addition of butanol. 