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Viral IgG Antibody to Hepatitis B Surface Antigen (Serum)

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

This test measures the presence of antibodies to the hepatitis B surface antigen in your blood. These antibodies indicate that your immune system has recognized and fought off the hepatitis B virus in the past.

Quick summary

["Past exposure to hepatitis B virus may be detected through these antibodies, even if you no longer have active infection symptoms."]

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

Key facts at a glance

LOINC
48160-6
Short code
HTLV I rgp21 Ab Ser Ql IB
Synonyms
HTLV I rgp21 Ab Ser Ql IB
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
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 Does This Test Measure?

The test detects hepatitis B surface antigen-specific IgG antibodies. These antibodies develop after your body has encountered the hepatitis B virus. Unlike IgM antibodies, which appear during an active infection, IgG antibodies suggest immunity from past infection or vaccination.

Why Might You Need This Test?

Healthcare providers may order this test to confirm past exposure to hepatitis B, assess immunity status, or evaluate immune response after vaccination. It can also help determine if you’ve developed immunity without experiencing symptoms.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab for analysis using an immunoassay method to detect IgG antibodies against the hepatitis B surface antigen.

What Are the Possible Results?

A positive result means you have IgG antibodies, indicating past infection or vaccination. A negative result suggests no detectable antibodies, meaning you may not have immunity from prior exposure or vaccination.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Hepatitis B IgG Antibody

Frequently asked questions

What does a positive result mean?
A positive result means your immune system has recognized and responded to the hepatitis B virus in the past, either through natural infection or vaccination. This typically means you have immunity and are unlikely to get hepatitis B again.
Can this test detect an active hepatitis B infection?
No, this test only detects past exposure or immunity. To check for an active infection, you would need additional tests for hepatitis B surface antigen (HBsAg) and hepatitis B virus DNA, along with IgM antibodies.
How long after exposure might it take to get a positive result?
IgG antibodies can take several weeks to months to develop after exposure. If you suspect recent exposure, follow-up testing with IgM antibodies or hepatitis B surface antigen may be needed to assess active infection status sooner.
  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