Isolation and characterization of exosomes using magnetic beads

Exosomes are extracellular vesicular structures (50–150 nm in diameter) secreted by all cells in culture and found in all body fluids investigated to date [1]. Exosomes function in diverse biological processes, including apoptosis, antigen presentation, angiogenesis, inflammation, and coagulation [2,3]. They have been observed to activate signaling pathways, as well as to deliver nucleic acids to distant cells [4–6]. Furthermore, tumor-derived exosomes can enhance cancer progression by transferring oncogenes from tumor cells to cells lacking the oncogene [7]. Both the concentration and composition of exosomes can vary significantly during disease. The isolation and characterization of exosomes from body fluids and cell culture systems will provide important information that may be useful for early disease detection, monitoring of disease status, and the development of effective treatments for cancer, inflammation, and autoimmune diseases. Further insight into exosome biology may also accelerate the use of these nanovesicles in regenerative medicine and vaccination research and increase the efficacy of therapeutic antibodies.