Lab Test

SARS-CoV-2 IgG (Anti-Spike)

Coronavirus, Corona, corona, Covid, covid, Covid-19

Test Codes


Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)

Physician Office/Draw Specimen Preparation

Let SST specimens clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged SST tube within two hours of collection. (Minimum: 2.0 mL) 

Preparation for Courier Transport

Transport: Centrifuged SST tube or serum aliquot, refrigerated (2-8°C or 36-46°F). (Minimum: 2.0 mL serum) 

Rejection Criteria

  • Hemolyzed specimens.
  • Severely lipemic specimens.
  • Specimens with obvious microbiological contamination

In-Lab Processing

Let SST specimens clot 30-60 minutes. Centrifuge SST or Microtainers® to separate serum from cells. Deliver immediately to the appropriate testing station.


Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers® with Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2-4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2-4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days 


Royal Oak Automated Chemistry Laboratory


Monday – Friday.
Results available within 3-5 days of receipt by the Laboratory.

Reference Range


Test Methodology



Presence of IgG antibodies to the spike protein of SARS-CoV-2 is a measure of immunological responsiveness to a previous viral exposure. Spike-specific antibodies can also be produced secondary to COVID-19 vaccination. A positive test result cannot be used to discriminate between an antibody response caused by a natural infection vs. vaccination. 

Antibody test result should always be interpreted together with clinical history and other results such as direct viral detection of SARS-CoV-2 (COVID-19). The performance characteristics of the EUROIMMUN test were determined by Beaumont Laboratory.  The test has been has been issued Emergency Use Authorization by the US Food and Drug Administration.   

Clinical Utility

  • Provide evidence of past exposure to SARS-CoV-2. Most individuals diagnosed with COVID-19 seroconvert within 3 weeks of exposure to the virus. If a specimen is collected too early (i.e. prior to seroconversion), the test will yield a negative result.
  • Provide evidence of antibody responsiveness to COVID-19 vaccination. It is not recommended to test for spike-specific antibodies until at least 3 weeks post-vaccination.  
  • The SARS-CoV-2 IgG assay is not a diagnostic test. Direct viral detection assays that employ molecular methods such as nucleic acid amplification, are the only laboratory tests that are diagnostic for COVID-19. 
  • IgG results should not be used to make decisions on infection status  

Incubation Period

According to estimates from the World Health Organization (WHO), the incubation period for SARS-CoV-2 ranges from 2-14 days with a median incubation period of 5 days. 

CPT Codes

LOINC 94507-1


Last Updated


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