Purified recombinant S/N proteins are immobilized to the surface of a multi-well plate to serve as capture antigens. The inactivated SARS-CoV-2 serum samples are placed with the antigen for the virus to promote binding to the antibodies. A secondary antibody serves as a label and binds to the viral antibodies to display a signal when a substrate is added (which can then be measured via photometry). The samples collected are blood serum samples from patients.