Exosomes are nanoscale vesicles (30-150 nm) secreted by almost all cells, with phospholipid bilayer structure, containing complex parent cells-deriving cargos including DNA, sRNA (mRNA, microRNA, and non-coding RNAs), proteins, lipids, and other substances. Exosome-carried cargo can reflect the status and molecular characteristics of parent cells. So isolating and extracting exosomes can help to study the functions and features of the parent cells and thus analyze diseases.