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Delta Bilirubin, Serum/Plasma — Mass Concentration

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

Measures delta (direct-reacting) bilirubin in blood, which is evaluated with other bilirubin tests to help assess liver function and jaundice.

Quick summary

["This blood test helps determine how much direct-reacting bilirubin is present, usually as part of an evaluation for jaundice or liver disease."]

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

Key facts at a glance

LOINC
1970-3
Short code
Bilirub Delta SerPl-mCnc
Synonyms
Bilirub Delta SerPl-mCnc
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?

This test measures delta bilirubin, also called direct-reacting bilirubin, in serum or plasma. Bilirubin is a yellow pigment produced when the body breaks down red blood cells, and it is processed by the liver.

Why might I need this test?

The test may be ordered to investigate jaundice, yellowing of the skin or eyes, or suspected liver or bile duct problems. It is usually interpreted alongside total bilirubin and indirect bilirubin.

How is the test performed?

A blood sample is collected, and the laboratory measures bilirubin in the serum or plasma using a validated chemical method. No special equipment is needed at home.

How do I prepare for the test?

Fasting is usually not required, but follow any instructions from your clinician or laboratory. Tell the healthcare team if you recently took a medicine that could affect liver function or bilirubin levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated direct-reacting bilirubin result may occur when the liver cannot adequately process or excrete bilirubin, such as with liver injury or blocked bile ducts. The result should be interpreted with total bilirubin, indirect bilirubin, symptoms, and other liver tests because a high value does not identify one specific condition by itself.

Short name

Direct bilirubin

Frequently asked questions

Is delta bilirubin the same as total bilirubin?
No. Total bilirubin measures all bilirubin in the sample, while delta bilirubin measures the fraction that reacts directly in the test.
Why are direct and indirect bilirubin both reported?
Comparing the fractions can help clinicians evaluate whether elevated bilirubin is more likely related to increased red blood cell breakdown, impaired liver processing, or impaired bile flow.
Does an abnormal result mean I have liver disease?
Not necessarily. Abnormal bilirubin can have several causes, so the result must be reviewed with your other laboratory findings, medical history, and symptoms.
  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