One of the first test systems to detect specifically protective RBD antibodies in Russia: RZN 2021/13925 dated March 30, 2021

Nowadays, ELISA test systems are mainly present on the market to detect antibodies to the SARS-CoV-2 antigen complex, which allow the detection of antibodies to coronavirus in patients who have undergone COVID-19 and vaccinated with Sputnik V. However, not all antibodies to SARS-CoV-2 are effective in the fight against COVID-19 and the above reagent kits do not allow the identified antibodies to be divided into "useful" and "useless". Based on the results of such studies, it is impossible to reliably judge the presence of "neutralizing" antibodies in patients.

Antibodies to antibodies - strife.
Studies aimed at finding mechanisms to combat coronavirus show that neutralizing ("beneficial") antibodies are only against the RBD site, which is the domain of the S1 protein. Penetrating into the body, the SARS-CoV-2 virus attacks cells with its spikes - Receptor-binding-domain (RBD), which are responsible for the entry of the virus into the cell.

Anti-RBD antibodies block these parts of the virus and thereby neutralize the virus, preventing SARS-CoV-2 from entering the cells of the human body. This principle of neutralizing the coronavirus was used in the development of the Sputnik-V vaccine. At the same time, it was revealed that anti-RBD antibodies are not produced in all COVID-19 patients - the necessary antibodies can be produced by the human body after vaccination, however, the effectiveness of vaccination and the presence of a protective titer of anti-RBD antibodies must be checked.

Those who have had COVID-19 for the presence of protective antibodies to the RBD antigen SARS-CoV-2

To control the formation of antibodies in the post-vaccination period

For selection of donors with the best indicators of the content of "protective" anti-RBD antibodies

To assess the risk of re-infection and determine the need for vaccination

The effectiveness of this set of reagents was confirmed in the study of the immune status of patients after vaccination with the Sputnik V vaccine.

Advantages of using the SARS-CoV-2 IgG RBD-IMBIAN-ELISA test

The reagent kit is designed for 96 determinations, including control samples, using an automatic enzyme-linked immunosorbent assay or using a manual test set-up.

Kit No. 1 of the kit of reagents consists of two-component (requiring preparation) solutions of conjugate and chromogen and is designed to study samples at a dilution of 1: 200 (preliminary dilution of samples is required).

Kit No. 2 consists of one-component (ready-to-use) solutions of conjugate and TMB and is designed to study samples at a dilution of 1:10 (no preliminary dilution of samples is required).
Separate independent assay settings with the required number of Immunosorbent strips are possible.

It is important both the presence of anti-RBD antibodies and their number, or titer, - the higher the antibody titer, the higher the likelihood that anti-RBD antibodies will neutralize the coronavirus, and you will not get sick.

To determine the protective antibodies, it is necessary to take an analysis to detect anti-RBD antibodies, as well as to identify the antibody titer, if any.

A set of reagents for the determination of class G immunoglobulins for the detection of class G immunoglobulins (IgG) to the receptor-binding domain of the surface glycoprotein S (spike) of the SARS-CoV-2 coronavirus in human blood serum (plasma) by the method of indirect enzyme-linked immunosorbent assay (ELISA) "SARS-CoV -2 IgG RBD-IMBIAN-ELISA "

Kit No. 1 options for staging:
with thermal shaker (135 minutes)
with thermostat (165 minutes)

With the help of ODcrit and the coefficient of positivity
There is a detailed instruction for determining the titer of a sample with a sample titration method

After opening, the reagent kit is stored for the entire shelf life

When assessing the strength of post-vaccination protective immunity by enzyme immunoassay, it is advisable to determine antibodies to the receptor-binding domain of anti-RBD antibodies (Temporary_MR_COVID-19_ (version 10 of 02/08/2021).

Kit No. 2 options for staging:
with thermal shaker (60 minutes)
with thermostat (95 minutes)