Figure 1.

Purification and characterization of microvesicles derived from SW480 cells. A) Overview of the procedure used to identify microvesicular and cellular mRNA from SW480 cells. B) Western blot of microvesicular marker proteins CD63 and CD81 in fractions from iodixanol density gradients. C) Electron microscopy of the purified microvesicles. Bars represent 100 nm. D) Western blot of β-actin, HSP90, Ezrin, and Rab5A (microvesicular proteins), and GM130 (a protein found in the cis-Golgi apparatus), and cytochrome c (a mitochondrial protein found in apoptotic bodies). Neither GM130 nor cytochrome c were detected in microvesicles, despite using 10 times more microvesicles (10 μg) than the amount used to detect other microvesicular proteins (1 μg). The symbols of WCL and MVs represent whole cell lysate and microvesicles, respectively.