Bilirubin, unconjugated and conjugated

By measuring at two different wavelengths unconjugated and conjugated bilirubin, respectively, can be determined. 

Drug or metabolite in sample Concentration up to which no interference occurred [mg/1] Concentration usually appearing in serum [mg/1] Interference, Clinically direction relevant [mg/1] 

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Serum ALP and total bilirubin (unconjugated and conjugated fractions) are traditionally used to monitor cholestatic injury. The ALP families of enzymes are zinc metalloproteases that are present in nearly all tissues. In the liver, ALP is immu-nolocalized to the microvili of the bile canaliculus [124]. Increased synthesis of ALP and its release into the circulation occurs within hours of cholestatic injury [129]. Serum assays of 5 -nucleotidase (5 -NT) or y-glutamyltransferase activity (GGT) are used to confirm the liver as the specific origin for the elevation of ALP. Increases in serum bilirubin or bile acids are usually the result of bile retention subsequent to impaired bile flow, increased production associated with accelerated erythrocyte destruction, or altered bilirubin metabolism [129]. 

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