Viruses are not amenable to filtering. You should do ultracentrifugation. What kind of supernatant are you working with? Is ist suitable für sterilisation?

Hi Mireia,

Are you doing filter sterilization? I'll check what we use for lenti and post it. maybe your titers are low so filtration cuts it back further? best of luck!

-ED

I think you want to filter a virus containing solution with the intention that the filtrate contains much of the virus but not anything larger? If I'm correct, for small volumes (under 50ml) you want 0.45um SFCA (e.g. thermoscientific 724-2045) or durapore PVDF filters (e.g. sigma Z355518-50EA). Do a short spin (e.g. 500g 3 mins) to pellet dead cells first or the filter will block and your yield will reduce. if you have a lot of supernatant, use a stericup. I use PVDF 0.45um stericups - product code SCHVU02RE, and am very pleased with them (for filtering retrovirus supernatant, should be similar for all enveloped viruses).