Vitrotest SARS-CoV-2 IgM TK034
SARS-CoV-2 IgM antibody test
The enzyme immunoassay kit is designed for the qualitative detection of IgM antibodies to the SARS-CoV-2 coronavirus. Detecting is based on a solid-phase type of enzyme immunoassay “IgM capture.” The IgM antibodies can be found after at least 7-11 days (9 days on average) after the first symptoms of the disease.
The patient’s venous blood serves as a sample for the test. Every test kit contains a vial on a special plate with an antigen on its bottom. The antigen incubates with the patient’s blood serum or plasma solution. Then, an added substrate solution changes color upon reaction. Finally, the results are determined spectrophotometrically.
When is an anti-SARS-CoV-2 test needed?
An antibody qualitative serological test is highly recommended for:
- infected people who passed the incubation period without or only with light symptoms but could spread the infection among others (so-called “silent” carriers);
- people who possibly contacted with persons infected with SARS-CoV-2 but do not correspond to requirements to make a PCR test;
- people who met the patients with SARS-CoV-2 to prevent viral contamination or confirm their immunity;
- patients with complications after recent influenza-like infection, which didn’t pass a coronavirus test;
- in case of an epidemiological study, to measure the scale of coronavirus spreading among people more precisely. The test doesn’t identify immune antibodies arising after vaccination against the coronavirus! If you need to determine the concentration of neutralizing antibodies created after a shot against COVID-19, you should do a SARS CoV-2 IgG antibody test. The test results are to interpret together with the patient’s actual medical symptoms and medical history. Due to the high sensitivity of the immunochromatographic assay, it is a screening test, so any positive IgM test result must be confirmed with another laboratory test.
Description of the SARS-CoV-2 antibody assay
Serological test kits don’t identify specific neutralizing antibodies to the SARS CoV-2 coronavirus and do complement the PCR testing method. However, the serological diagnosis becomes vital at later stages of infection as the sensitivity of the molecular diagnosis descends due to decreasing the number of virus particles in the respiratory epithelium.
The IgM antibodies in the venous blood serum are “early-stage” consequences of the infection, so their presence can indicate an active phase of the disease. Therefore, a positive test result, the presence of IgM antibodies, does not always mean a final confirmation.
A test made too early can give a false-negative result during the so-called “serological gap” — a period when a specific humoral immune response is not being seen. Sometimes, even a positive test result can be caused by a passed or actual infection with coronavirus variants different from SARS-CoV-2, e.g., NL-63, HKU-1, or OC-43.
The SARS-CoV-2 IgM antibody test results should not be considered an ultimate indicator to confirm or deny the SARS-CoV-2 coronavirus disease and inflammatory processes in the human body.
