Characterization of human exosomes.

A, the median diameter of exosomes measured by a nanoparticle analyzer was 115 ± 0.9 nM; n = 5 separate samples. B, electron microscopy of isolated exosomes verifies diameter size measured by the particle analyzer. C, western blot showing enrichment of CD63 (green), an exosomal protein marker, when compared to the originating cells, n = 4.