IgG Antibody to SARS-CoV-2 (Spike Protein) - Serological Test
This test measures the presence of IgG antibodies against the spike protein of SARS-CoV-2, the virus responsible for COVID-19. These antibodies develop after infection or vaccination and can indicate past exposure or immunity.
["IgG antibodies may help confirm past COVID-19 infection or assess immunity after vaccination."]
Key facts at a glance
- LOINC
- 27435-7
- Short code
- Deprecated S pneum19 IgG sp1 Ser IA-mCnc
- Synonyms
- Deprecated S pneum19 IgG sp1 Ser IA-mCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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 This Test Measures
IgG antibodies are a type of immune protein your body produces in response to infection or vaccination. This test specifically looks for antibodies directed against the spike protein of the SARS-CoV-2 virus. These antibodies can appear weeks to months after infection or vaccination and may persist long-term, offering clues about your immune response.
Why It’s Done
Doctors may order this test to determine if you’ve had a past COVID-19 infection or if your immune system has developed antibodies after vaccination. It can also help monitor immune response in certain clinical situations.
Sample Collection and Preparation
A blood sample is taken from a vein in your arm. The blood is processed to separate serum, which is then tested for IgG antibodies. This test does not require fasting or special preparation beyond standard blood draw procedures.
When Results Might Be Useful
Positive results suggest you’ve likely been exposed to the virus or vaccinated and developed immunity. Negative results mean you either haven’t been exposed or haven’t developed detectable antibodies yet. Results may vary depending on timing after exposure or vaccination.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG antibody testing can support diagnosis of past infection, guide vaccination decisions, or assess immune status in high-risk individuals. While IgG indicates a strong immune response, it does not guarantee protection against reinfection. Interpretation should always be done by a healthcare provider in the context of your medical history and symptoms.
Short name
IgG Anti-Spike Antibody
Frequently asked questions
When would I need this test?
What do my results mean?
Does this test replace a COVID-19 PCR test?
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