Hi. you can centrifuge at 35000 rpm for 1 hour than resuspend the pellet with growth medium DMEM OR RPMI. ideally you should not have to concentrate after transfection but i suspect that you already tried to improve the transfection.

Best regards

Thanks Martin, I tried untracentrifugation using sucrose cushion, but were able to reach to only around 100ng/ml titre . Need to take it to around 200 odds. Transfection protocol is well standardized already.

T

Hi Muzamil,

I have used Lenti-X concentrator (from Clontech) following the general protocol provided by the manufacturer. It worked very well and it allows you to use a normal centrifuge (4000 rpm). A little bit expensive, though, depending on the volume of virus you need to concentrate.

Good luck

It would be much easyer to help you if I new how your protocol are set up :) The titer depend on wich virus you are working with - but I can not relate to ng/mL I hav always measured infectious units/ML or TCID50...

If you are willing to try funny stuff, you could go with caffeine- it should increase the titer for lentivirus but I have never tried it my self...