Characterization of exosome-rich extracellular vesicles (EVs) derived from human osteosarcoma or osteoblastic cell lines. EVs were isolated from 24 hours conditioned culture medium obtained from osteosarcoma (SAOS2, MG63, U2OS, HOS, and 143B) and osteoblastic (hFOB1.19) cells. Diameter size (nm) distribution and concentration of purified EVs were determined by NTA (A), and mode size (nm) of three replicates were plotted (B). Relative number of secreted EVs contained in equal volume aliquots of purified EVs was normalized to 1 million of cells (C). Relative concentration of small RNA (ng) into EVs contained in equal volume aliquots of purified EVs was determined and normalized to amount of EVs secreted by 1 million cells (D).