The Rapid IgM-IgG Combined Antibody Test for COVID-19 is a lateral flow immunoassay used to qualitatively detect both early and late marker IgG/IgM antibodies in human finger-prick blood samples.
It is widely accepted that Immunoglobulin M (IgM) provides the first line of defence during viral infections, followed by the generation of adaptive, high affinity Immunoglobulin G (IgG) responses for long-term immunity and immunological memory. Therefore, testing of COVID-19 IgM and IgG antibodies is an effective method for the rapid diagnosis of COVID-19 infection.
Detection of IgM antibodies tends to indicate a recent exposure to COVID-19.
Detection of IgG antibodies indicates a later stage of infection.
The testing device has a strip, which contains a colloidal gold-labelled recombinant novel coronavirus antigen and quality control antibody colloidal gold marker, two detection lines (G and M lines) and one quality control line (C) fixed on a nitrocellulose membrane. M is fixed with monoclonal anti-human IgM antibody for detecting the novel coronavirus IgM antibody. G is fixed with monoclonal antihuman IgG antibody for detecting the novel coronavirus IgG antibody.
Results are within 15 minutes after the blood sample and buffer have been combined in the testing device’s sample well.
It has been acknowledged that our German made COVID-19 immunoassay devices are of a very high quality. The medical device contained within our kits has an EC-Declaration of Conformity with the Essential Requirements Annex I of the Directive 98/79/EC of the European Parliament and of the Council of 27 October 1998 on in vitro diagnostic medical devices. The sensitivity of our immunoassay is the best we have observed and is greater than 99.9% diagnostic sensitivity for IgG detection, and 91.8% diagnostic sensitivity for IgM detection. The diagnostic specificity for IgG reaches 99.5%, whereas the diagnostic specificity for IgM is 99.2%.
A total of three detection lines are possible. The control (C) line appears when the sample flows through the testing device cassette.
If only the quality control (C) line appears, then no novel coronavirus antibody has been detected and the result is negative.
Positive Result, M only
If both the quality control line (C) and the detection line M appears, then the novel coronavirus IgM antibody has been detected and the result is positive for the IgM antibody.
Positive Result, G only
If both the quality control line (C) and the detection line G appears, then the novel coronavirus IgG antibody has been detected and the result is positive for the IgG antibody.
Positive Result, G and M
If the quality control line (C) and both detection lines G and M appear, then the novel coronavirus IgG and IgM antibodies have been detected and the result is positive for both the IgG and IgM antibodies.