SARS-CoV-2 & Influenza Antigen Combo Rapid Test Kit

The SARS-CoV-2 & Influenza Antigen Combo Rapid Test Kit is an in vitro immunochromatography assay for the qualitative and differential detection of nucleocapsid (N) protein antigens from influenza A (including the H1N1 subtype), Influenza B, and SARS-CoV-2 viruses in human oropharyngeal swab, nasal swab and nasopharyngeal swab specimens. It is intended to aid in the rapid diagnosis of these three viral infections in patients, which present similar respiratory symptoms and so are difficult to diagnose from clinical evaluation alone. All three viruses have epidemic potential, so proper diagnosis is important for treating patients and controlling the diseases.

The test consists of two parallel immunochromatographic membrane assays. When the sample is added to the well, the solution migrates up the membrane due to the capillary effect. In the SARS-CoV-2 test, if there are SARS-CoV-2 N protein antigens present in the sample, then these will be bound by monoclonal anti-SARS-CoV-2 N protein antibodies conjugated to colloidal gold, which are present in the test strip. These migrate with the solution to the test (T) line position on the membrane, which is coated with immobilized anti-SARS-CoV-2 N protein antibodies. These also bind the antigens, such that conjugated antibody-SARS-CoV-2 N protein-capture antibody complexes accumulate at the T line, and a red line is formed. In the Influenza test strip, the same principle is followed. If there are Influenza A N protein antigens present in the sample, these are bound by colloidal gold conjugated anti-Influenza A N protein antibodies, and are captured by anti-influenza A N protein antibodies coated to the test strip to form a line at the A position; Influenza B antigens present in the sample and monoclonal anti-Influenza B N protein antibodies similarly form a line at the B position. Therefore, the presence of lines at the T, A, and B positions ten minutes after adding the sample can be used in the positive diagnosis of SARS-CoV-2, Influenza A, and Influenza B infections respectively, whilst the absence of each line indicates a negative result.

On both strips, to serve as a procedural control, a red line will always appear at the control (C) position. If this C line is absent after ten minutes, the result is invalid, and the test should be repeated using a new cassette.