Quantification of SARS-CoV-2 anti-RBD IgG antibodies against the RBD domain of the spike protein

The viral spike protein is composed of S1, S2 and RBD domains. In SARS-CoV-2-anti-S quantification of antibodies (including IgG) against the spike protein, we looked for antibodies against the entire viral spike protein (S1, S2 and RBD).

During SARS-CoV-2 anti-RBD quantitative IgG antibody detection against the RBD domain of the spike protein, we are looking for antibodies against only one specific part of the viral spike protein - the RBD. Part of the RBD binds the virus to the human cell and thus enters it. Therefore, it is important to know exactly how many antibodies will be formed against this part of the virus, which is directly responsible for our protection against the virus.

During the quantitative determination of SARS-CoV-2-anti-S antibodies (including IgG) against the spike protein, we detect all classes of antibodies against the spike protein of the SARS-CoV-2 virus (IgA, IgM, IgG) in the blood. The more different classes of antibodies we detect, the higher the result.

During SARS-CoV-2 anti-RBD quantitative determination of IgG antibodies against the RBD domain of the spike protein, we detect only IgG class antibodies against the RBD part of the viral spike protein. Accordingly, the amount of those antibodies is lower (we are looking for only one class of antibodies and only against one part of the viral spike protein).