Bacterial cultures were first centrifuged at 15,000 x g for 10 min at 4 °C in a tabletop centrifuge (Heraeus Megafuge 16R, Thermo Scientific, Waltham, USA) to remove bacterial mass. The supernatants were filtered through 0.22 µm PES bottle top filters (Fisher Brand, New Hampshire, USA) and concentrated approximately 10-fold by tangential flow filtration (VivaFlow 200, 100 kDa cutoff, polyethersulfone, Sartorius, Göttingen, Germany). The concentrate was then ultracentrifuged for 2 h at 150,000 xg and 4 °C in a Beckman Optima LE-80K (Beckman Coulter, Brea, USA). The supernatant was discarded, and the pellet was washed twice in 1 mL ultrapure water. Afterward, the BMV pellet was resuspended in 1 mL ultrapure water and stored at 4 °C for a maximum of 1 week.
Would you expect a difference in vessicle stability or selective depletion more labile vesicles (e.g., smaller/unsaturated or protein-rich)?