Urinalysis - The Carter Center

cell disease (hepatocellular disease) and obstruction of the bile flow from
the liver (Obstructive or post - hepatic jaundice).
Urine containing bilirubin will typically have been brown color and
produce a yellow foam when shaken. Bilirubin is not stable in solution,
but will be oxidized to biliverdin, which is a green pigment. Thus urinecontaining
bilirubin will typically be red-brown when voided, and will turn
green on standing, especially if exposed to light. Tests for bilirubin will
not be positive in the presence of biliverdin; so the urine must be
examined when fresh.
Tests for Bilirubin
Tests for bilirubin are based on the oxidation of bilirubin to biliverdin.
Specimen: Freshly passed urine is required. Urine containing bilirubin
should be analyzed immediately after collection (with in 2 hrs of voiding).
If bilirubin exposed to sunlight, it will oxidize to biliverdin, which cannot
be detected by the reagents used in any of the tests. The following tests
are used to detect bilirubin in the urine.
A. Harrison's (Fouchet's) Test
Principle
This test depends on precipitation of bilirubin with barium chloride, which
is then oxidized to biliverdin with Fouchet's reagent. The formation of
biliverdin gives a green color, which constitutes a positive reaction.
Procedure
1. Add 5 ml of a 10% solution of barium chloride to 10 ml of urine.
Mix, and let stand a Few minutes.
2. Filter through a small filter paper.
3. Spread the filter paper on a dry piece of filter paper and place one
or two drops of Fouchet's reagent.
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