Briefly, E. coli polar lipid extract was dissolved in chloroform to a concentration of 0.10 mg/100 L. DiO was dissolved in chloroform to a concentration of 1.0 mg/400 L. Aliquots of 400 L (0.40 mg) of the E. coli lipid solution and 18.4 L (45.9 g) of the DiO solution were combined in a 50 mL round bottom flask and the chloroform was evaporated off under an N2 stream until visibly dry. The round bottom flask was kept in the dark to limit the exposure of the DiO dye to light. Trace amounts of chloroform was removed by further drying the lipid-DiO mixture under vacuum (95 mbar) for 2 hours at room temperature. Lipid containing DiO was rehydrated at room temperature in 1 mL of 0.1 M NaCl and 10 mM phosphate buffer (PB) at pH 7. The lipid solution was gently mixed and then vortexed for ~1 minute and left to sit for 30 minutes to rehydrate. Liposomes were formed by extrusion with an Avanti Mini Extruder using a 100 nm extrusion membrane (Avanti Polar Lipids) and were passed through the membrane 51 times.