Evaluation of purification methods of EVs

One of the challenges that restricts the growth of extracellular vesicle (EV) research field is the lack of a standardized method for EV separation. In this study, three commonly used EV separation methods, ultracentrifugation, precipitation and size exclusion chromatography (combined with ultrafiltration with a microfluidic tangential flow filtration device, Exodisc) was used to comprehensively evaluate the EV yield and sample purity from cell culture medium, human urine and plasma.

The isolated EVs were assessed in terms of their yield, purity and surface protein expression by the Flow NanoAnalyzer. Using these parameter, practical recommendations were made for the choice of isolation and purification methods based on sample type and downstream applications. 

                         Figure 1. Concentrations of particles separated by different methods                       Figure2.  Purity of EV samples assessed by

                                                                                                                                        particle/protein ratio

Figure 3. Composition purity analysis of EVs by DGUC           Figure 4. Purity of EV samples assessed by single particle phenotyping

Figure 5. The decision tree on how to select the proper EV separation method based on the input sample

In this study, the author characterized EVs by the Flow NanoAnalyzer with multiple parameters, evaluated purification methods suitable for different sample types, concluded how to select suitable purification methods based on different sample sources and downstream applications, and provided practical recommendations.

J Extracell Vesicles, 2020, 10(2):e12044.