Serological diagnosis in the course of COVID-19 is important at a later stage of the disease, between 7th and 10th days after infection. The coronavirus antibody test detects antibodies in two classes.
IgM are characteristic for the “early stage” of the disease. Their detection allows the determination of possible contact with the virus, and the presence of these antibodies in the sample may be indicative of an active infection. They are detectable from 7-10 days to about a month after the infection or the occurrence of the symptoms of the disease.
IgG are antibodies of the late phase of the infection. They are determined to check the presence of immune antibodies after the coronavirus infection. If they are present in the test sample, it indicates the development of immune resistance and indicates a history of the disease and contact with the SARS-CoV-2 virus. They are detectable 11-14 days after the onset of the symptoms of the disease and their level increases with time.
Several types of samples are accepted: blood, plasma, serum. The test for the presence of antibodies in the organism provides results very fast – a result for the presence of IgM and IgG antibodies can be interpreted as soon as after just 15 minutes. It is possible to perform the test in two steps by adding the sample and the diluent respectively. IgM and IgG antibodies are detected by a single chemical reaction. The test is extremely simple to use.