The COVID-19 S-RBD IgG Antibody Test Cassette is a fluorescence immunoassay for the semi-quantitative detection of IgG antibodies to SARS-CoV-2 spike(S) protein receptor binding domain(RBD) in human whole blood, serum or plasma specimen.It is intended for use as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2.