Abstract: The present invention relates to an affinity isolation system and method using a switch-like binding reaction. An affinity isolation system according to an embodiment of the present invention comprises: a ligand (10); a binder (20) to which the ligand (10) is reversibly bound and which structurally changes with the binding reaction thereof with the ligand (10); a recognition material (30) specifically binding to the structurally changed binder (20); an immobilizing member (40) having a surface onto which any one of the binding pair, the binder (20) and the recognition material (30), is immobilized; and a capturing material (50) conjugating with the other of the binding pair, the binder (20) and the recognition material (30), to form a conjugate (C) and specifically binding to the target (1) in a target subpopulation from a sample solution.

Abstract: The present invention relates to a technique in which a target exosome subpopulation, a sub-subpopulation, or a lower population in human fluid, which is associated with a specific disease, is isolated and recovered in its intact form at high yield to prepare a liquid biopsy sample and analyzed.