Isolation and Characterization of Exosomes from Cell Culture Supernatants and Biological Fluids

TLDR

Exosomes are small membrane vesicles released from multivesicular bodies into cell culture supernatants and biological fluids, characterized by a defined set of membrane and cytosolic proteins, and are increasingly implicated in diverse biological processes despite their functions remaining debated. The study emphasizes the need for high‑quality exosome purification from cell‑culture supernatants and biological fluids due to their differing lipid membranes. This unit outlines various exosome purification strategies from multiple sources and evaluates the purity and homogeneity of the preparations.

Abstract

Exosomes are small membrane vesicles found in cell culture supernatants and in different biological fluids. Exosomes form in a particular population of endosomes, called multivesicular bodies (MVBs), by inward budding into the lumen of the compartment. Upon fusion of MVBs with the plasma membrane, these internal vesicles are secreted. Exosomes possess a defined set of membrane and cytosolic proteins. The physiological function of exosomes is still a matter of debate, but increasing results in various experimental systems suggest their involvement in multiple biological processes. Because both cell-culture supernatants and biological fluids contain different types of lipid membranes, it is critical to perform high-quality exosome purification. This unit describes different approaches for exosome purification from various sources, and discusses methods to evaluate the purity and homogeneity of the purified exosome preparations.