Virus Concentration by PEB Precipitation

1. Infect cells and allow to incubate for as long as necessary to approach maximum virus production for the strain and cell type combination.
2. Collect culture media/supernatant at 3000rpm for 15 minutes to remove cells and cell debris.
3. Collect supernatant and add 1 volume of PEG solution to 4 volumes of virus containing supernatant.
4. Refrigerate overnight (stable up to 2 weeks @ 4°C).
5. Centrifuge at 2300rpm for 45 minutes. After centrifugation, virus particles may appear as a beige or white pellet at the bottom of the tube.
6. Remove supernatant.
7. Resuspend virus pellet in 1/10 to 1/100 of original volume using cold sterile PBS or DMEM.
8. Aliquot in small aliquots and store at -70°C until use.

Procedure gives 1 to 2 log increase in final infectious virus titer.