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Conjugated Bilirubin, Serum/Plasma — Substance Concentration

Published: August 9, 2026Updated: August 16, 2026

Measures conjugated bilirubin in blood, which helps evaluate how the liver processes and excretes bilirubin.

Quick summary

["This blood test helps assess liver processing of bilirubin, particularly when jaundice or elevated total bilirubin is present."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
29760-6
Short code
Bilirub Conj SerPl-sCnc
Synonyms
Bilirub Conj SerPl-sCnc
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

Conjugated bilirubin is bilirubin that has been changed in the liver so it can be excreted in bile. This test measures its concentration in serum or plasma.

Why might I need this test?

Your clinician may order this test as part of a liver function panel, especially if you have jaundice, dark urine, pale stools, or an abnormal total bilirubin result. It can help distinguish between different patterns of liver-related bilirubin elevation.

How is the test performed?

A blood sample is collected, and the laboratory measures conjugated bilirubin using a validated laboratory method. The result is usually reported along with total bilirubin and other liver function tests.

How do I prepare for the test?

Fasting is often unnecessary for this test when it is ordered alone, but fasting may be required for a broader laboratory panel. Follow your clinician's or laboratory's preparation instructions and tell them about any medicines or supplements you use.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Conjugated Bilirubin

Frequently asked questions

What is conjugated bilirubin?
It is bilirubin that the liver has chemically modified so it can be released into bile. It is measured to help evaluate liver function.
Is this the same as a direct bilirubin test?
Conjugated bilirubin is often included in what laboratories call a direct bilirubin measurement, but the exact reporting method can vary. The test name and laboratory results should be reviewed with your clinician.
Does an abnormal result mean I have liver disease?
Not necessarily. Conjugated bilirubin can be affected by liver conditions, bile duct obstruction, medications, and other factors, so it must be interpreted with other tests and your clinical findings.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy