Fig. 2.

Exosome isolation methods. Example procedures and comparison of 4 commonly used methods, which are ultracentrifugation, ExoQuick precipitation, immunoaffinity pulldown/magnetic-activated cell sorting using anti-EpCAM (MACS) and OptiPrep density gradient to isolate exosomes from a plasma sample. These are compared in terms of purity, exosome yield, ease of use, approximate isolation time, approximate hands-on time and approximate cost per sample. *=low, **=moderate, ***=high, ****=very high. The relative assessment of procedures for exosome purity, yield, ease of use, isolation time, hands-on time and cost are adapted from Van Deun et al. (22).