FIELD: chemistry.
SUBSTANCE: group of inventions relates to methods and sets for determining biological activity of neurotoxins. Disclosed is a method for direct determination of biological activity of a neurotoxin polypeptide in cells, involving incubation of cells susceptible to neurotoxin intoxication, with neurotoxin polypeptide; fixation of cells; bringing the cells in contact with at least the first binding antibody specifically binding to the unsplated and neurotoxin-split substrate, and at least a second binding antibody specifically binding to the cleavage site of the substrate cleaved by the neurotoxin; bringing the cells into contact with at least a first detecting antibody specifically binding to the first binding antibody, thereby forming first detectable complexes, and at least a second detection antibody specifically binding to a second binding antibody, thereby forming second detectable complexes, where the first detecting antibody and the second detecting antibody are conjugated with different enzymes; determining the number of first and second detectable complexes and determining biological activity of said neurotoxin polypeptide in said cells. Kit for implementing said method is also disclosed.
EFFECT: group of inventions provides direct determination of biological activity of the neurotoxin polypeptide in cells without additional stages of lysis and separation or concentration of the split neurotoxin substrate from cell lysates.
16 cl, 3 dwg, 5 ex
