Team:Northwestern/OMV purification

Adapted Extracellular Vesicle preparation protocol:

1. Grow desired volume of E. coli liquid culture until mid-log phase (OD₆₀₀ = 0.5-0.8)
2. Take note of exact OD₆₀₀
3. Pellet the cells gently (approx. 6,000 g) for 5 minutes
4. Recover as much supernatant as possible without disturbing the cell pellet
5. Leave some supernatant behind if necessary
6. Take note of the volume recovered
7. Filter the supernatant using a 0.22 µm syringe filter unit to remove any remaining cells
8. Change unit if and whenever it clogs
9. Equilibrate a 14 kDa centrifugal filter unit with PBS
10. Concentrate the filtered supernatant with the centrifugal filter unit following manufacturer’s instructions
11. Once all the supernatant has been concentrated, if desired, buffer exchange using the same centrifugal filter unit (e.g. with PBS prior to a SDS-PAGE)
12. Sample is ready for analysis.