2.2. Isolation and Characterization of Exosomes from BxPC3 and AsPC-1

An Exosome Isolation Kit (Denmark) was used to isolate exosomes (Exos/BxPC3 and Exos/AsPC-1) from BxPC3 and AsPC-1 cells per the manufacturer's instructions. Briefly, BxPC3 and AsPC-1 cells were cultured to 85% confluence in 6-well plates; after which, the cell supernatants were collected and exposed to Exosome Concentration Solution at 4°C. The mixture was then allowed to rest for 2 h at 4°C prior to centrifugation. The collected exosome pellets were purified using an Exosome Purification Filter and collected for subsequent use. For particle size measurement, the collected exosomes were resuspended in prechilled PBS and stained with 2% phosphotungstic acid (pH 6.8), and their morphology features were observed under a transmission electron microscope. The exosomes were also verified by western blotting with anti-TGS101 antibodies and anti-CD63 antibodies. The particle size of exosomes was also characterized by size distribution using particle size analyzer (N30E, NanoFCM).