The SG Diagnostics COVID-19 Antigen Rapid Test Kit is an immunochromatographic membrane assay that uses highly sensitive antibodies to detect SARS-CoV-2 spike and nucleocapsid protein antigens from swab samples via the double antibody sandwich method. After loading, the sample will diffuse upwards from the charging end by capillary action, and then the SARS-CoV-2 spike and nucleocapsid protein antigens in the sample will combine with the antibody in the marker pad to form colloidal gold antibody-antigen complex; the complex continues to diffuse upwards to the nitrocellulose membrane with the sample, and then blocked by Test (T) Line packed with antibody to form colloidal gold labeled antibody-antigen-immune complex. The rest unblocked colloidal gold complex continues to move upwards and combine with the Control (C) line (quality control line), indicating that the reaction is completed. – Read IFU for more information.