Urine Diagnostics / Urine Test Strips / Portfolio Urine Test Strips / Urobilinogen
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|The test is based on the coupling of urobilinogen with a stabilised diazonium salt.|
The practical detection limit is around 0.5 mg/dl (8.5 µmol/l),
|The test is specific for urobilinogen. A yellow coloration indicates large quantities of bilirubin. Occurrence of green or blue coloration (after more than 60 sec.) due to other bilirubin degradation products is very rare.|
|Sources of errors|
Formaldehyde can cause false-negative results. Direct sunlight leads to oxidation of the urobilinogen and to diminished values.
Pharmaco-metabolites, which show a red colouration at low pH (phenazopyridines, beetroot, azo dyes, p-aminobenzoic acid), can cause false-positive results.
|Urobilinogen is formed by bacteria from bilirubin, which is secreted from the bile into the intestine. Most of the urobilinogen is reabsorbed, passed to the liver via the portal vein, further decomposed and is also partly eliminated in urine. The normal urobilinogen concentration in urine ranges from 0.1-1.8 mg/dl (1.7-30 µmol/l), concentrations >2.0 mg/dl (34 µmol/l) are considered to be pathological. Urobilinogen does not occur in urine, unless bilirubin gets into the intestines. Urobilinogenuria can be accompanied by bilirubinuria, although this is not necessarily the case. Increased urobilinogen is eliminated in urine if the functional capacity of the liver is overloaded, limited or the liver is bypassed. Urobilinogen can be excreted by the kidneys.|