[Advances in separation techniques for exosomes and their clinical applications].

Exosomes are vesicles secreted by many types of cells through exocytosis, and their sizes range from 30 to 200 nm. Exosomes consist of a lipid bilayer membrane, containing a number of bioactive molecules, e. g., proteins, ribose nucleic acid (RNA), and deoxyribo nucleic acid (DNA) derived from the cell of origin. As intercellular communication carriers, exosomes participate in many physiological and pathological processes. Because of the complexity of body fluids, as well as the small size and low density of exosomes, the isolation of exosomes is an essential and challenging step before subsequent analysis and functional studies. This review summarizes the advances in the analytical approaches, characterization methods, biological functions and clinical applications of exosomes, with particular emphasis on exosomes isolation techniques.