Serological Test for Antibodies Against SARS-CoV-2 (COVID-19) – Qualitative Detection
This test checks for the presence of antibodies in your blood that your immune system produces in response to exposure to the COVID-19 virus.
Determines if your body has developed immunity to COVID-19 through past infection or vaccination.
Key facts at a glance
- LOINC
- 97109-3
- Short code
- NEWEMPLOYMENTDURINGTHECOVID19OUTBREAK
- Synonyms
- —
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 5
- Critical range
- 2.5 N/A – 6.5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84132
- SNOMED
- 110742001
- 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 Antibodies Are Measured?
This test typically detects two main types of antibodies: IgM and IgG. IgM antibodies appear early after infection and usually decline over time. IgG antibodies develop later and can persist longer, indicating a stronger immune response. Some tests may also look for neutralizing antibodies, which help protect against future infection.
When Might You Need This Test?
You may need this test if you’ve been exposed to COVID-19, have symptoms, or are recovering from the illness. It can also be used to assess immunity after vaccination or to monitor immune response in certain clinical situations.
How Is the Test Performed?
A blood sample is drawn from a vein in your arm. The sample is then tested in a lab to detect specific antibodies against the virus. Results are qualitative, meaning they only indicate whether antibodies are present or not.
What Do the Results Mean?
A positive result means your body has detected the virus and produced antibodies, suggesting past infection or vaccination. A negative result means no detectable antibodies were found at the time of testing. Results do not confirm current infection and may not be accurate immediately after exposure or vaccination.
Reference range
Adult: 3.5-5.0 mmol/LN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test plays a key role in understanding immune response to COVID-19, guiding decisions about vaccination, exposure risk assessment, and monitoring for immunity. However, it is not a diagnostic tool for active infection and should not replace other tests like PCR or antigen tests for current illness.
Short name
COVID-19 Antibody Test (Serum/Plasma)
Frequently asked questions
Why did my doctor order this test during the COVID-19 outbreak?
What does a positive antibody test mean for my health?
Can this test be used to confirm if I had COVID-19 recently?
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