Techniques used for the isolation and characterization of extracellular vesicles: Results of a worldwide survey

Extracellular vesicles (EV_s) represent an important mode of intercellular communication. Research in this field has grown rapidly in the last few years, and there is a plethora of techniques for the isolation and characterization of EV_s, many of which are poorly standardized. EV_s are heterogeneous in size, origin and molecular constituents, with considerable overlap in size and phenotype between different populations of EV_s. Little is known about current practices for the isolation, purification and characterization of EV_s. We report here the first large, detailed survey of current worldwide practices for the isolation and characterization of EV_s. Conditioned cell culture media was the most widely used material (83%). Ultracentrifugation remains the most commonly used isolation method (81%) with 59% of respondents use a combination of methods. Only 9% of respondents used only 1 characterization method, with others using 2 or more methods. Sample volume, sample type and downstream application all influenced the isolation and characterization techniques employed.