Characterization of exosomes released by MIN6B1 cells. A) The sizes of microvesicles isolated by ultra-centrifugation from the culture media of MIN6B1 cells was measured using the Nanosight technology. B, C) Three different preparations of microvesicles from MIN6B1 cells were analyzed by immunoblotting for B) the presence of the exosomal protein markers Alix, CD81 and Tsg101, and C) for the absence of the cellular protein Calnexin. Cell extract was used as positive control for the detection of Calnexin. D) RNA profiles of MIN6B1 cells (upper panel) and of microvesicles (lower panel) were determined by Bioanalyzer.