SARS-CoV-2 Immunoglobulin M (IgM) Antibody Test, Serum/Plasma
This test detects antibodies (specifically IgM) your body produces in response to exposure to the SARS-CoV-2 virus, which causes COVID-19. IgM antibodies typically appear shortly after infection but may not be present long-term.
["IgM antibodies signal an acute immune response to COVID-19, often appearing within days of infection but declining as your body produces other protective antibodies."]
Key facts at a glance
- LOINC
- 108785-7
- Short code
- SARS-CoV-2 IgM Msmt SerPl
- Synonyms
- SARS-CoV-2 IgM Msmt SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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?
This test measures the presence of IgM antibodies in your blood or plasma. IgM is one type of antibody your immune system makes early in response to a virus like SARS-CoV-2. It helps identify whether you may have recently been infected, though it may not be detected as long as other antibody types (like IgG) remain present.
When Might This Test Be Used?
Doctors may order this test to help determine if you had a recent COVID-19 infection, especially if symptoms appeared shortly after exposure. It can also be used in research or screening settings where early detection of infection is important.
How Is the Test Performed?
A blood sample is taken from a vein in your arm. The sample is then sent to a lab where it is analyzed using an immunoassay method to detect IgM antibodies against the SARS-CoV-2 virus.
What Are the Possible Results?
A positive result means your blood contains IgM antibodies, suggesting you may have been infected with SARS-CoV-2 recently. A negative result means these antibodies were not detected in your sample at the time of testing. Results can vary depending on when you were tested relative to your exposure or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgM antibodies are a key part of your immune response to COVID-19. While they appear early after infection, they tend to decline over time as your body shifts to producing other protective antibodies (like IgG). This test can help confirm recent infection, especially when combined with clinical symptoms or exposure history. However, IgM alone may not be sufficient for diagnosing infection in all cases, particularly if testing occurs too early or too late in the infection timeline.
Short name
IgM Antibody to SARS-CoV-2
Frequently asked questions
Why might I need this test?
What does a positive IgM result mean?
Can IgM antibodies be detected after I’ve recovered from COVID-19?
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