Exosome Isolation and Characterization

Culture medium was centrifuged at 3000g for 15 min, and filtered through a 0.22-µm PVDF filter (Millipore) to remove cells and cellular debris. Then the filtered culture medium was mixed with the Exoquick exosome precipitation solution (System Biosciences, CA, USA) at a ratio of 1:5 and refrigeration for at least 12 h. Thereafter, the mixture was re-centrifuged at 1500g for 30 min, the supernatant was discarded and exosomes were collected. Purified exosomes were resuspended in approximately 100 μL of PBS and subjected to transmission electron microscopy (TEM) (× 200) (JEOL, Akishima, Japan), cell co-culture, RNA extraction with Trizol reagent or protein detection with RIPA lysis buffer [30 (link)].