Urobilinogen
Definition
A colourless bile pigment metabolite produced by intestinal bacteria from bilirubin. It is excreted in faeces (as urobilin/stercobilin) and detected in forensic analysis by Ehrlich's reagent, providing a chemical indicator of faecal material.
- Type
- Colourless bile pigment metabolite
- Produced by
- Intestinal bacteria acting on bilirubin
- Detection reagent
- Ehrlich's reagent
- Forensic target
- Faecal material identification
Common questions
What does a positive Ehrlich's reagent reaction actually indicate?+
Ehrlich's reagent reacts with urobilinogen and its oxidation products to give a characteristic colour change, which supports the presence of faecal material on an item but is treated as presumptive, not confirmatory, on its own.
Why is urobilinogen useful when the sample is old or degraded?+
Its breakdown products, urobilin and stercobilin, are chemically stable pigments, so they remain detectable on fabric or surfaces well after the original faecal deposit has dried or partially decomposed.
Related terms
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