Characterization of OSCC cell-derived exosomes.

<p>(A) Immunolabeling of exosomes derived from OSC-4 cells. Purified exosomes were transferred to copper grids and immunostained with mouse anti-human CD63 followed by rabbit anti-mouse antibody and colloidal gold coated with protein A (10 nm). Samples were stained with uranyl acetate and analyzed by transmission electron microscopy. Scale bar = 100 nm. (B) Total cell lysate (TCL) and exosomes (Exo) from OSC-3 and OSC-4 cells were analyzed by western blotting with antibodies against CD9, CD63, Rab5B, Annexin II, Calnexin, and Cytochrome C.