Figure 1.

Isolation of exosomes from Colo-320 cells. (A) Experimental procedure for isolation of exosomes from conditioned medium of Colo-320 cells. Cells were cultured in serum-free conditions for 72 h before collection of the medium, which was then sequentially centrifuged at 300× g to remove cells and large debris and at 10,000× g to remove larger EVs such as microvesicles. Medium was then concentrated by tangential flow filtration and spin filtration to a final 1.0 mL volume. Exosomes were finally isolated by size exclusion chromatography (SEC). (B) A representative SEC elution profile showing the protein concentration of the 70 fractions (0.5 mL each) typically collected. (C) Dot blot showing the fractions containing exosomes, based on the presence of the exosomal marker CD81.