FIELD: biology.SUBSTANCE: group of inventions relates to the detection of target-oriented drugs. Method for determining the biological response of a target to a soluble candidate substance comprises the following steps: introducing a soluble candidate substance into a laminar flow of a buffer liquid flowing through a dispersion channel to form a candidate substance solute in the buffer liquid having an initial concentration profile; by the laminar flow of the buffer liquid through the dispersion channel dispersing said candidate substance solute such that a dispersed concentration profile is formed in the buffer liquid; directing the laminar flow of the buffer liquid containing the candidate substance solute having said dispersed concentration profile into a detection channel to form a final symmetrical concentration profile of the candidate substance solute in the buffer liquid in the detection channel; introducing a target into the detection channel for mixing with the candidate substance solute, having a f
