AccuFind COVID19 IgG is designed for qualitative determination of IgG antibodies to the SARS-CoV-2 in human serum, plasma (sodium citrate, sodium heparin, EDTA), or venous whole blood. The test uses mixed recombinant SARS-CoV-2 nucleocapsid protein (N protein) and spike protein (S protein) both conjugated with colloidal gold and anti-human IgG antibody coated on a test line. After the samples has been applied to the test strip, the gold-labelled recombinant SARS-CoV-2 N protein and S protein will bind with SARS-CoV-2 IgG antibody in sample and form marked antigen-antibody complexes. These complexes move to the test card detection zone by capillary action. Then marked antigen-antibody complexes will be captured on the test line by anti-human IgG antibody resulting in purplish a red streak on the test lines. The color intensity of the test line increases in proportion to the amount of SARS-CoV-2 IgG antibody in sample.