SARS-CoV-2 (Covid-19): Diagnosis by IgG/IgM Rapid Test

SARS-CoV-2 (Covid-19): Diagnosis by IgG/IgM  Rapid Test

For a rapid detection of anti-SARS-CoV-2 (2019-nCoV) IgG and IgM in 10-15 minutes during Covid-19

COVID-19 (Corona Virus Disease) is an infectious disease caused by the most recently discovered coronavirus, SARS-CoV-2 (2019-nCoV).

The rapid test for SARS-CoV-2 diagnosis provides qualitative detection of IgG and/or IgM from human serum, whole blood or plasma in approximately 10-15 minutes.

The rapid tests are based on the principle of lateral flow immunoassay chromatography and are available in cassette form. The test is based on the separation of the components of a mixture through a medium using capillary force and the specific and rapid binding of an antibody to its antigen.

IgM and IgG are immunoglobulins produced by the immune system to provide protection against SARS-CoV-2. Anti-SARS-CoV-2 IgM and IgG can therefore be detected in samples from affected patients.

We offer several types of kits to detect either IgG or IgM or both at the same time. We also offer kits containing only the cassettes and other complete kits for sampling and testing. All of these kits arefor in vitro diagnostic use and can only be used by healthcare professionals.

What are the advantages of the Rapid tests :

  • Rapid-screening within 10-15 minutes.
  • High detection efficiency: simultaneous monitoring of IgM and IgG.
  • Detection without any testing equipments .
  • Easy to operate, and is compatible with serum/ whole blood/ plasma.
  • Room-temperature storage.

What is the principle of the Rapid tests for SARS-CoV-2

The test detects the presence of patient-generated antibodies against SARS-CoV-2, the virus which causes the disease COVID-19. The test can detect two types of antibody isotypes: IgG and IgM.

There are several types of tests but the most common one consists of fixing anti-human IgG and IgM antibodies to the surface of the cassette and coupling an antigen of the virus with colloidal gold particles. If the patient sample contains anti-SARS-CoV-2 antibodies then these antibodies will bind to the antigen present in the conjugation pad of the cassette and the complex formed will migrate to the membrane-bound anti-human IgG and/or IgM. A colored band will then appear (see below for possible results).

The level of IgM antibody begins to rise after 1 week after the initial infection, while the IgG appears later than IgM (usually in 14 days after infection) and can last for 6 months or even several years, which means that the IgG serves as an indicator of previous infection. Suspected patients that are infected by SARS-CoV-2 can be rapidly identified by simultaneous monitoring of IgM and IgG. During the outbreak period of 2003-SARS and the 2016-Zika, IgM / IgG antibody detection was used as one of the recommended diagnostic methods.

A sample can be positive if there are IgM, IgG, or both IgM and IgG antibodies present.

There are different cassettes for the rapid tests. In general, for the qualitative detection of IgG and IgM in the same time, there are 3 different lines : one for IgG, one for IgM and one for the control.

To be validated, this test have to present a positive line for control (C)

IgM+ / IgG+
Recent infection with SARS-CoV-2
IgM+ / IgG-
Recent infection with SARS-CoV-2
IgM- / IgG+
Previous infection with SARS-CoV-2
IgM- / IgG-
No infection or not enough detectable antibodies in the early infection

Medical devices for in vitro diagnosis. Read the operating instructions carefully.
All of these kits arefor in vitro diagnostic use and can only be used by healthcare professionals.