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Principle: The test paper contains a stable diazonium salt producing a reddish azo compound with urobilinogen.
Evaluation: Depending on the urine colour 0.5 to 1 mg urobilinogen/dI urine are indicated. 1 mg/dl is considered to be the normal excretion rate. Higher values are pathological. A complete absence of urobilinogen in the urine, which is likewise pathological, cannot be detected with the strips. The colour fields correspond to the following urobilinogen concentrations:
normal (0 - 1), 2, 4, 8,12 mg/dl or
normal (0 - 17), 34, 70,140, 200 μmol/l.
The test is inhibited by higher concentrations of formaldehyde. Longer exposure of the urine to light leads to lowered or falsely negative results. Higher, or falsely positive results, can be caused by the presence of diagnostic or therapeutic dyes in the urine. Larger amounts of bilirubin produce a yellow colouration.
Diagnosis: An increased urobilinogen concentration in urine is a sensitive index of liver dysfunction or hemolytic diseases. Urobilinogenuria is caused by e. g. virus hepatitis, chronic hepatitis, liver cirrhosis, infections, poisonings, congestion or carcinoma of liver, hemolytic, and pernicious anemina, polycythemia and pathological state of the intestinal tract with an increased resorbence.
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