Fig 1: Characterization of exosomes. A. Morphological characterization of exosomes derived from AZ-P7a, AZ-521, and SBC-3 cells by transmission electron microscopy. B. Immunoelectron micrographs of AZ-P7a exosomes labeled with immunogold anti-CD63. Exosomes with black colloidal gold particles on the capsular membranes were observed as positive CD 63 staining under the transmission electron microscope (arrowheads). C. Molecular characterization of exosomes derived from AZ-P7a, AZ-521, and SBC-3 cells by western blot analysis. Protein extracts (10 µg) prepared from cells (C) or exosomes (Ex) were assessed using antibodies against exosomal protein markers (CD29/β1-integrin, Aip1/Alix, and Tsg101) and an endoplasmic reticulum marker (Bip/Grp78).