ИСТИНА

Adsorption of antibodies to tularemia Francisella tularensis (F. name of the genus) on the surface of gold-plated glass chips and the subsequent reaction of antigen-antibody were studied by surface plasmon resonance (SPR) technique. It was found that these antibodies tend to polylayer adsorption on the gold surface. However, washing with a buffer solution leads to desorption of weakly associated molecules, and the monomolecular coating with the same parameters remains on the surface for all initial concentrations of antibody in the solution. The antibody monolayer characterized by surface protein concentration near 2.6 ng/mm2. This value corresponds to the area of about 100 nm2 per molecule of the immunoglobulin. This first adsorption layer adjacent to the surface irreversibly binds to it, which makes it possible to use such a system for subsequent diagnosis of tularemia microbes in solution. It was shown that rapid determination of the microbe in solution up to concentrations of 1.0 × 102 mcl / ml can be carried out using such biosensors using the SPR method. Based on the estimated area per molecule of the adsorbed antibody in the monolayer and the comparatively low signals of the antigen-antibody reaction, a conclusion was made about the lateral arrangement of the antibody molecules in the adsorption layer. The sensitivity of the proposed method can be improved by creating an oriented layer of antibody molecules, which promotes more effective interaction with the antigen.