I did not change the media the day after transfecting 293T cells. Are they going - (Aug/18/2010 )

So I transfected 293T cells with 5 different plasmids. I was supposed to change the media the next day, but I did not. Instead I did it 2 days later.

It has been three days after the transfection and I collected the viral supernatant as I was supposed to. The plates look very confluent and the cells look like they are coming off the plate. Do you think that the viral supernatant can still be used for transduction or is it likely to be very low titer? Thanks!

We have harvested several days post transfection with some diminished transduction efficiencies compared to correct harvest protocols. However, if your "to be" transduced cells can be selected with antibiotic (say if you were transducing with a virus containing a shRNA that also codes for say puromycin resistance),there might be more cells dead due to a lower MOI of your virus, but the cells that survive antibiotic resistance will still provide target cells for expansion. Your MOI may be lower due to degradation of the lentiviral particles, but in the end, you should still obtain successfully transduced cells.