A High Through-Put Assay For Circulating Antibodies Directed Against The S Protein Of Severe Acute Respiratory Syndrome Coronavirus 2 (Sars-Cov-2).

Over three million infections with the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) were confirmed globally by May, 2020. While PCR-based assays are used for diagnosis, high through-put, rapid serologic methods are needed. A Luminex binding assay was developed and used to assess simultaneously the presence of COVID-19-specific antibodies in human serum and plasma. Clear differentiation was achieved between specimens from infected and uninfected subjects, and a wide range of serum/plasma antibody levels were delineated in infected subjects. All 25 specimens from 18 COVID-19 patients were positive in the assays with both, the trimeric spike and the receptor-binding domain (RBD) proteins. None of the 13 specimens from uninfected subjects displayed antibodies to either antigen. There was a highly statistically significant difference between the antibody levels COVID-19-infected and -uninfected specimens (p<0.0001). This high through-put antibody assay is accurate, requires only 2.5 hours, and uses 5 nanograms of antigen per test.