2.5. Immunogold electron microscopy
The exosomes pellets were fixed with 2% PFA and deposited onto formvar carbon-coated electron-microscopy grids for 20 min. The grids were transferred to 50 mM glycine three times for 3 min each time, and then blocked with 5% BSA for 10 min. Immunogold staining was conducted by incubating the sections with a rabbit anti-LOX-1 (1:200, Abcam) antibody overnight at 4℃, followed by incubation with anti-rabbit 5 nm IgG gold (1:50, Boster) for 1 h. The grids were separately transferred into 1% glutaraldehyde and stained by adding 2% uranyl acetate. After air dry, the grids were viewed under electron microscopy.