SARS-CoV-2 IgG (Spike protein)

This test is a chemiluminescent immunoassay (CLIA) intended for the qualitative and semi-quantitative detection of IgG antibodies to SARS-CoV-2 in human serum, and plasma (lithium heparin and dipotassium EDTA). The test is intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection.

At this time, it is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity. This test should not be used to diagnose or exclude acute SARS-CoV-2 infection.


Results are for the detection of SARS CoV-2 antibodies. IgG antibodies to SARS-CoV-2 are generally detectable in blood several days after initial infection, although the duration of time antibodies are present post-infection is not well characterized. Individuals may have detectable virus present for several weeks following seroconversion.

Negative results do not preclude acute SARS-CoV-2 infection. If acute infection is suspected, direct testing for SARS CoV-2 is necessary (SAL Test # 2018). False positive results may occur due to cross-reactivity from pre-existing antibodies or other possible causes. Samples should only be tested from individuals that are 15 days or more post symptom onset.

Test results are reported as positive or negative along with a numeric value for semi-quantitative measurement for values between 13 AU/mL and 800 AU/mL. Results above 800 CU are reported as >800, Results below 13 CU are reported as <13

This test is only for use under the Food and Drug Administration's Emergency Use Authorization.