TEST SYSTEM FOR DETECTING ANTIBODIES TO STRUCTURAL PROTEINS OF FOOT-AND-MOUTH DISEASE VIRUS STRAIN "SAT-1/KENYA/2017" USING LIQUID-PHASE BLOCKING INDIRECT "SANDWICH" VERSION OF ELISA Russian patent published in 2024 - IPC C12N15/00 G01N33/569 

FIELD: veterinary science; virology; biotechnology.

SUBSTANCE: described is a test system for detecting antibodies to structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" using a liquid-phase blocking indirect "sandwich" version of ELISA, containing: immunospecific lyophilised components: cultured inactivated lyophilised foot-and-mouth disease virus strain "SAT-1/Kenya/2017" with activity in ELISA 1:4000; sensitizing antibodies – rabbit immunoglobulins G against structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" with activity in ELISA 1:8000; detector antibodies – guinea pig immunoglobulins G against structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" with activity in ELISA 1:4000; control 1 – strongly positive blood serum of calves against structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" with percentage of inhibition of 75–100%; control 2 – positive blood serum of calves to structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" with inhibition percentage from 50% to 74.9%; control 3 – negative blood serum of calves, which does not contain antibodies to antigen of foot-and-mouth disease virus; cattle blood blocking serum; anti-species conjugate – rabbit immunoglobulins against guinea pig Ig G conjugated with horseradish peroxidase, with activity in ELISA 1:4000; non-specific components: a buffer solution based on sodium carbonate and hydrogen carbonate with pH 9.5–9.6; 20-fold concentrate of buffer solution, chromogenic substrate – diammonium salt of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate), stop solution – 0.7% solution of sodium salt of laurylsulphuric acid. Advantage of the developed test system is a long storage life (not less than 5 years) due to production of lyophilized immunospecific components. Proposed test system is the first in the Russian Federation, modern, specific and sensitive, intended for quantitative determination of antibody titre against structural proteins of foot-and-mouth disease virus strain "SAT-1/Kenya/2017" in wide range 1:16...1:4096 for subsequent analysis of immune status of animals with respect to foot-and-mouth disease. This strain and the corresponding genotype are relevant and quickly spreading on the territory of the African continent and the Middle East.

EFFECT: created test system is aimed at confirming the high efficacy of inactivated foot-and-mouth disease vaccines produced in the Russian Federation, containing the antigen of the given genotype of the foot-and-mouth disease virus, and thereby protecting the territory of Russia and neighbouring countries in the south from the spread of the foot-and-mouth disease virus isolates of the strain "SAT-2/Kenya/2017".

2 cl, 3 dwg, 5 tbl, 6 ex