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Bilirubin
Short Description : Bilirubin- Serum/Plasma
Also known as : [Total Bilirubin]

Plasma/Serum
Test performed by: LabPLUS Automation

Specimen Collection

Protect from sunlight. Up to 50% decrease in one hour in direct sunlight.

Sample stability:

Total Bilirubin

  • 1 day at 15-25 o C
  • 7 days at 2-8 o C
  • 6 months at -20 o C

Direct Bilirubin

  • 2 days at 15-25 o C
  • 7 days at 2-8 o C
  • 6 months at -20 o C


PST

4.5 mL PST Blood (Preferred)

Micro-PST

0.5 mL Paediatric Micro-PST Blood (Preferred)

Heparin

5 mL Heparin Blood

Plain

4 mL Plain Serum

SST

3.5 mL SST Blood

Microsample

0.5 mL Paediatric Microsample Blood

Micro-heparin

0.5 mL Paediatric Micro-heparin Blood

Micro-SST

0.5 mL Paediatric Micro-SST Serum
Reference Intervals

Total Bilirubin

Units: umol/L

Age:

Cord blood

<50

up to 24 hrs

24 to 48 hrs

48 to 72 hours

<150

<200

<250

3 to 7 days

7 days to 3 weeks

3 to 4 weeks

<300

<100

<50

4 weeks to Adult:

<25

pregnancy:

<16

  • Paediatric values are for full term infants.

  • Action thresholds may differ in cases of prematurity, rhesus disease or sick neonates.

  • Uncertainty of Measurement : 8% at a level of 10 umol/L
    5% at a level of 380 umol/L

    • Conjugated (Direct) Bilirubin

    Neonate: <20 umol/L

    Child and Adult: 0-5 umol/L

    • As of 09/12/2021, the assay for DIRECT bilirubin changed from Roche to Randox. The Randox Direct bilirubin assay is much more resistant to haemolysis interference. In depth in-house evaluation showed that the two assays give highly comparable results, no significant inter-assay difference is expected.

    Uncertainty of Measurement : 6%

  • Conversion factor:

    mg/100 mL x 17.1 = umol/L
    umol/L x 0.0585= mg/100 mL

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    Turnaround Time: Within 3 hours
    Diagnostic Use and Interpretation

    Total bilirubin

    Increased in intrahepatic and extrahepatic biliary obstruction, hepatocellular damage, and haemolytic diseases.

    Conjugated (direct) bilirubin

    This is bilirubin conjugated to glucuronide, and is increased in biliary obstruction (intahepatic or extrahepatic).

    Unconjugated bilirubin

    The level of unconjugated bilirubin is calculated by subtracting the conjugated bilirubin from the total bilirubin.

    Unconjugated bilirubin is increased when there is excess production (haemolytic states) and/or impaired uptake or conjugation by the liver (neonatal jaundice, Gilbert's syndrome).

    Moderate increases (usually < 40 umol/L and rarely > 80 umol/L) in unconjugated bilirubin, in the absence of haemolysis, are seen in Gilbert's disease, a relatively common and benign condition.



    Last updated at 14:59:14 09/02/2022