Figure 1.

Exosome characterization: (A) Exosomes were isolated from supernatants of Kasumi-1, a human leukemia cell line using mini-SEC as described in Materials and Methods. Exosomes in Fraction #4 were harvested and characterized by tunable resistive pulse sensing (TRPS) to determine their diameters and concentrations (left); by Western blots to show the presence of exosome markers and absence of cytoplasmic proteins (middle); and by TEM to illustrate vesicular morphology and the size range (right). (B) The TEM images, size distribution profiles and Western blot profiles of Mel526 exosomes (left) and exosomes produced by human T cells (middle). (a) The size distribution profile of circulating exosomes in CD-1 mouse plasma; (b) comparisons of total exosomal protein levels of circulating exosomes in the plasma of CD-1 mice and of normal human donors. The data are means ± SD from 3 independent measurements.