Fig. 2

Characterization of exosomes isolated from the conditioned medium of neural stem cells (NSC-exo) and mature neurons (MN-exo). a) Representative high-resolution transmission electron microscopy image of exosomes secreted from NSC and from MN, derived from the differentiation of NSC, isolated using the ultra-centrifugation method (scale bar = 100 nm). b) Total protein lysates of isolated exosomes were analyzed by western blotting for the presence of exosome-specific proteins, CD63, CD9, HSP70, CD81, and the absence of the Golgi-associated protein GM130 as a control for cellular contamination. Total brain lysate was used as positive control. Please note that the western blot in (B) is a composite image of several blots shown here in aggregate for clarity and demonstrative purposes. Images are representative of over 20 independent experiments using hippocampus NSC between passages 6–10. c) Nanoparticle tracking analysis (NanoSight NS300, Malvern Panalytical, Malvern, UK) of exosomes isolated from NSC and MN shows a homogenous size distribution with an average single peak at 72.3 nm (NSC-exo) and 69.4 nm (MN-exo) (data is representative of 3 independent exosome preparations)