The Unibiosciene Covid-19 Antibody Test Kit is an immunochromatographic lateral flow assay for the detection of SARS Cov-2 antibodies in whole blood, capillary blood, serum or plasma. This assay uses anti-human IgM antibody (test line IgM), anti-human IgG (test line IgG), and anti-mouse IgG (control line C) immobilized on a nitrocellulose strip. The conjugate pad contains recombinant SARS-Cov-2 antigen (spike protein RBD domain major antigens of SARS-Cov-2) conjugated with colloid gold. During the assay, the sample binds to the SARS-Cov-2 antigen conjugated gold colloid coated particles in the assay cassette. When a sample followed by assay buffer is added to the sample well, IgM and/or IgG antibodies, if present, bind to the COVID-19 conjugates and form an antigen-antibody complex. This complex migrates through the nitrocellulose membrane by capillary action. When the complex encounters the line of the corresponding immobilized antibody (anti-human IgM &/or anti-human IgG), the complex is captured and forms a colored line confirming a reactive test result. The absence of a colored line in the test region indicates a non-reactive test result. For procedural control, a colored line appears in the control line region indicating that the correct sample volume has been added and the membrane has been wicked. Failure of a colored line to appear in the control line region indicates an invalid test..