The Biohit SARS-CoV-2 IgM/IgG Antibody Test is based on the immunochromatographic method. The SARS-CoV-2 IgM/IgG is detected by SARS-CoV-2 recombinant N-protein antigen and mouse anti human IgM/IgG antibody. SARS-CoV-2 IgM/IgG in the sample reacts with SARS-CoV-2 recombinant N-protein antigen bound to gold particles. This complex migrates along the membrane and reaches the IgM/IgG test line (T) which contains mouse anti human IgM/IgG antibody against SARS-CoV-2 IgM/IgG complex. The sample diluent is supplied for the lateral chromatography process, to provide a suitable environment for the reaction of antigen and antibody.
When the result is positive, the gold-labelled SARS-CoV-2 recombinant antigen-antibody complex binds to the IgM/IgG test line (T) and a purplish red color develops. When the result is negative, the sample does not contain any SARS-CoV-2 recombinant N-protein antigen-antibody complex that can bind to the IgM/IgG test line (T) so no color becomes visible. Development of a purplish red control line (C) helps ensure the addition of sufficient specimen volume and adequate migration have occurred and that the test was properly performed.