SARS-CoV-2 Immunoglobulin G (IgG) Antibody Test by Titer (Serum/Plasma)
This test measures the level of IgG antibodies in your blood that your immune system produces in response to exposure to the virus that causes COVID-19.
["IgG antibodies indicate past infection or immunity from COVID-19."]
Key facts at a glance
- LOINC
- 95429-7
- Short code
- SARS-CoV-2 IgG Titr SerPl IF
- Synonyms
- SARS-CoV-2 IgG Titr SerPl IF
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 8
- Ref high
- 61
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- if
- CPT
- 82977
- SNOMED
- 3110003
- 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?
IgG antibodies are a type of antibody your body makes after recovering from an infection or after vaccination. They provide long-term immunity. This test checks the concentration of these antibodies in your serum or plasma to determine if your immune system has recognized and responded to the SARS-CoV-2 virus.
Why Might You Need This Test?
Your healthcare provider may order this test if you have had COVID-19 symptoms, suspect past exposure, or if you are recovering from COVID-19 to assess your immune response. It can also be used in research or clinical studies to track immunity.
Sample Collection and Preparation
A blood sample is taken from a vein in your arm. The blood is processed to separate serum or plasma, which is then tested for IgG antibodies. This process helps ensure accurate measurement of the antibodies in your system.
What Does a Positive Result Mean?
A positive result means your body has produced IgG antibodies against the SARS-CoV-2 virus, suggesting you have likely had an infection at some point or have been vaccinated. However, IgG alone does not confirm current infection; it indicates past exposure or immunity.
Reference range
Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG antibodies are crucial for long-term immunity against COVID-19. High levels may indicate a strong immune response, potentially offering protection against future infections. However, antibody levels can vary and may not always correlate directly with protection over time. This test can help guide decisions about vaccination, exposure assessment, or monitoring immunity in clinical settings.
Short name
IgG Antibody to SARS-CoV-2
Frequently asked questions
How Long Does It Take to Get Results?
Can IgG Antibodies Protect Me from Getting COVID-19 Again?
Do IgG Antibody Levels Change Over Time?
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