Current Methods to Purify and Characterize Exosomes

Abstract Exosomes are small extracellular vesicles released by cells in a controlled manner. The exosomes have a number of newly defined functions in the extracellular space including paracrine signaling and transferring proteins and small RNAs between cells. In order to study exosomes they must be isolated from cell culture media or biofluids. The efficiency of this exosome isolation and the purity of the resulting exosome preparation are critical for studying these extracellular vesicles. In this chapter, we present well-established protocols for exosome isolation and characterization. For each protocol presented, we provide a best-use case, a rational for each step, and a brief discussion of the advantages/disadvantages. The goal of this chapter is to provide easy-to-follow protocols as well as an understanding of how best to choose an exosome purification and characterization method to suit their studies.