This in vitro diagnostic ELISA assay is designed for qualitative detection of IgG antibodies specific for the SARS-CoV-2 spike protein in human serum. It uses an indirect ELISA format on a 96-well microplate, requiring 10 µL of sample, with a total incubation time of 105 minutes and a 450 nm read wavelength. Storage at 2-8°C. Negative (Non-Reactive) results indicate no detectable IgG; positive (Reactive) results suggest presence of spike-protein IgG antibodies, to be interpreted alongside vaccine or infection history.