VLD 411: Veterinary Clinical Biochemistry and Laboratory Diagnosis - I (0+1)

BILE PIGMENTS

• Normally, bilirubin is present in freshly voided urine. On standing, it is converted into biliverdin (green colour), bilicyanine (blue) and cholestelin (violet, red, reddish yellow).
• Iodine ring test
• A sensitive cum reliable test
• Layer a solution of 10% alcoholic iodine on urine in a test tube
• A green colour indicates presence of bile
• Harrison test
  • A sensitive test
  • To 5 ml of urine add 5 ml of 10% barium chloride in a test tube
  • Shake and filter it off
  • Let the filter paper dry
  • Then add 1-2 drops of Fouchet’s reagent
  • A green colour indicates bilirubinuria
• Gmelin’s test
  • Bile pigments are oxidized by acids to coloured derivatives.
  • Take 2 ml of concentrated nitric acid in a test tube
  • Add 2 ml of urine along the side of the test tube
  • At the junction of the two fluids, a play of colour – green, blue, violet etc. will be observed if bile pigment is present

Interpretation

• Moderate to severe hepatocellular damage
• Obstruction of bile ducts, extrahepatic or intrahepatic
• In early hepatocellular damage and haemolysis urine bilirubin may be negative.