The COVID-19 IgG + IgM Rapid Test Kit (Colloidal Gold) is a qualitative membrane-based immunoassay for the detection of antibodies against SARS-CoV-2 antigens in whole blood, serum or plasma. This test can help determine if a subject has been exposed to the novel SARS-CoV-2 coronavirus, which causes COVID-19 disease.
When the mixed sample and buffer solution are added to the sample well, the solution migrates to the test membrane by capillary effect. If there are anti-SARS-CoV-2 antibodies in the sample, they bind to the SARS-CoV-2 antigens conjugated to colloidal gold, which are present on the membrane; these migrate together across the membrane to the test line regions.
Mouse anti-human IgG monoclonal antibodies are coated onto the IgG test line, and these capture any IgG antibodies in the sample, so that the antibody-sample IgG antibody-antigen-colloidal gold capture complexes accumulate on the line. IgG. Similarly, mouse anti-human IgM monoclonal antibodies coated on the IgM test line can capture any IgM antibody present in the sample, such that the antibody-antigen-colloidal gold IgM sample capture complexes accumulate in the IgM line. The accumulation of colloidal gold produces a visible line that indicates a positive result for IgG and / or IgM. If the sample does not contain COVID-19 antibodies, no colored line will appear in any of the test line regions, indicating a negative result. Test results should be read after 10 minutes.
To serve as a procedural control, a colored line will always appear in the control line region (C), indicating that the appropriate volume of sample has been added and membrane absorption has occurred. If the control line is absent, the result is invalid and must be repeated with a new sample and a new cassette.
The in vitro diagnostic reagents used in the test are compared to the clinical diagnostic criteria for novel coronavirus pneumonia to verify the clinical performance of this product. The cases included were suspected cases of new coronavirus infection, a total of 1,585 cases, including 421 confirmed cases and 1,164 excluded cases. A comparative study was conducted using in vitro diagnostic reagents for tests and clinical diagnostic criteria for novel coronavirus pneumonia. The test results show that the product has a clinical sensitivity of 98.81% (95% CI: 97.25%, 99.61%) and a clinical specificity of 98.02% (95% CI: 97 , 05%, 98.74%).
In addition, 203 subjects received homologous serum / plasma and whole blood samples (125 of which were positive and 78 negative) for comparative testing. The results show that the product is based on the results of the serum / plasma tests, and the consistency rate of the results of the whole blood tests is 96.85% (95% CI: 95.87 % to 97.60%). After preliminary evaluation, it is basically confirmed that the clinical performance of the COVID-19 IgG + IgM (Colloidal Gold) Rapid Test Kit can meet the emergency use requirements of the epidemic.