Immunoassay for COVID-19 Antibody Detection (Serum/Plasma)
This test measures antibodies in your blood that your immune system produces in response to COVID-19. It helps determine if you’ve been exposed to the virus, even if you didn’t experience symptoms.
This test can help track immunity and guide decisions about vaccination or future exposure.
Key facts at a glance
- LOINC
- 97089-7
- Short code
- HOWOFTENMEDICALPROVIDERSUSEDASSOURCEOFINFORMATIONFORCOVID19
- Synonyms
- —
- 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 the Test Measures
The test detects two main types of antibodies: IgM and IgG. IgM antibodies appear early after infection and typically fade over time. IgG antibodies develop later and can persist longer, indicating long-term immunity. Some tests may also check for neutralizing antibodies, which help protect against reinfection.
How the Test Works
Blood is drawn from a vein, usually in your arm, and sent to a lab. The serum or plasma is then analyzed using an immunoassay method to identify specific antibodies against SARS-CoV-2, the virus that causes COVID-19. The results are compared to a standard to determine antibody presence.
When You Might Need This Test
Healthcare providers may recommend this test if you’ve had COVID-19 symptoms, were exposed to someone with COVID-19, or if you’re planning to donate blood. It can also be used to assess immunity after vaccination or prior infection.
Preparation and Process
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if instructed. The blood draw is quick and typically painless. Results are usually available within a few days, depending on lab processing times.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
COVID-19 Antibody Test (Serum/Plasma)
Frequently asked questions
Positive results indicate that your immune system has recognized and responded to the virus, which may mean past infection or vaccination. However, antibody levels can vary widely and may not always correlate directly with immunity. Always follow guidance from your healthcare provider for interpretation.
Negative results mean your body hasn’t produced detectable antibodies against COVID-19 at this time. This could mean you haven’t been exposed or infected recently, but it doesn’t guarantee future protection.
This test is not a replacement for regular COVID-19 vaccination or booster shots, which remain the best way to prevent severe illness and long-term complications.
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