Serum or plasma concentration of viral antibody (IgG) to hepatitis B virus
This test measures the presence of antibodies in your blood that your immune system produces in response to hepatitis B virus infection. These antibodies indicate past exposure to the virus or immunity from vaccination.
["IgG antibodies to hepatitis B help determine if you’ve been exposed to the virus or vaccinated against it."]
Key facts at a glance
- LOINC
- 14224-0
- Short code
- HTLV I rgp21 Ab Ser Ql
- Synonyms
- HTLV I rgp21 Ab Ser Ql
- Category
- chemistry
- 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 This Test Measures
The test detects IgG antibodies specific to the hepatitis B virus surface antigen. IgG antibodies are typically long-lasting and can indicate immunity developed either through natural infection or vaccination. This test is often used to confirm immunity after vaccination or to assess past exposure.
Why It’s Done
Healthcare providers may order this test to: check if you’re immune to hepatitis B after vaccination, evaluate whether you’ve been exposed to the virus, or monitor chronic hepatitis B infection. It’s also used in screening for blood donors and in certain high-risk populations.
How It Works
A blood sample is taken and analyzed using an immunoassay method to detect IgG antibodies. The test measures the concentration of these antibodies in your serum or plasma.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves a fasting blood draw, but this is not always required for antibody testing. Wear comfortable clothing and plan to stay near the testing site for a short time.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Hepatitis B IgG Antibody
Frequently asked questions
If your test result is positive for hepatitis B IgG antibodies, it suggests you have immunity to the virus. If you received the hepatitis B vaccine, this result confirms protection. If you’re unsure about your vaccination status or exposure, this test can help determine your risk and guide further medical advice.
What does a positive result mean?
Can this test detect acute hepatitis B infection?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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