Measurement of total bilirubin by use of bilirubin oxidase.

Abstract

We used an enzymatic method for measuring total bilirubin in serum. Results by this method varied linearly with bilirubin concentrations to at least 300 mg/L. The day-to-day precision (CV) of the method ranged from less than 1% to about 11% at bilirubin concentrations of 183 and 12 mg/L, respectively. Commonly used anticoagulants, serum preparation materials, and selected drugs had no effect on the apparent bilirubin concentration, but turbidity caused a slight increase and hemoglobin concentrations of 2 g/L resulted in lower values, by as much as 17 mg/L at a bilirubin concentration of 95 mg/L. Patients' results obtained with this enzymatic method were slightly lower than those obtained with methods based on the Jendrassik-Grof principle. The largest differences, seen in samples with high "direct" bilirubin concentrations, can be decreased by measuring the absorbance at 425 nm instead of at 465 nm as recommended by the supplier of the bilirubin oxidase method.

Fluorescent protein-based detection of unconjugated bilirubin in newborn serum

“…Parenteral alimentation with lipids is normally provided as nutrition to preterm infants or sickly newborns 19 . Although the bilirubin oxidase method is affected by the presence of serum hemoglobin and lipid emulsion 11 , we found in this study that hemolysate or serum containing emulsion did not affect unconjugated bilirubin measurement by the UnaG method. Additional studies are required to determine whether the various drugs used in clinical neonatal medicine interfere with UnaG-based detection.…”

“…A major disadvantage of these conventional methods is to produce an inaccurate result in serum samples with turbidity. For example, the bilirubin oxidase method measures bilirubin levels by monitoring a change in absorbance at 450 nm, which is affected by turbidity due to hemoglobin or lipid emulsion 11 . High-performance liquid chromatography is the only method for directly measuring unconjugated bilirubin 12 , but is impractical for routine clinical use.…”

Bile composition in inflammatory bowel disease: ileal disease and colectomy, but not colitis, induce lithogenic bile

“…Total bilirubin concentrations were determined enzymatically using the bilirubin oxidase method 17 . Preliminary studies in our laboratory showed that results obtained using this assay correlated strongly ( n = 10 bile samples, r = 0.997) with those obtained using the Jendrassik–Grof diazo method of measurement of bilirubin concentrations, which has been reported to be less susceptible to interference by photobilirubin 18 …”

Use of deproteinizer to eliminate interference of high bilirubin on measurement of serum creatinine by the kinetic jaffe reaction

“…21,22 Oxidation of both conjugated and unconjugated bilirubin to biliverdin by either bilirubin oxidase or horse-radish peroxidase and hydrogen peroxide and the subsequent oxidation of biliverdin to a pale Diazonegative polar pigment cause characteristic absorption peaks of bilirubin to disappear. [23][24][25] Broderson and Bartels noted that albumin inhibits the oxidation, suggesting that dissociation of bilirubin from albumin or other carrier proteins could facilitate its oxidation. 23 Low pH as well as several compounds that binds to proteins promotes the displacement of bilirubin from albumin.…”