Posted 28 October 2009 - 05:15 PM
If you got these phoenix cells comercially they should have protocols for transfection with ideal conditions- its probably wise to follow their recommendations.
If not, then....
I haven't used those particular 293 cells, but I have used other 293 for viral production and low passage number for the cells is important for transfection efficiency- the younger the better. Also don't let your cells get too confluent, around 60-70% is optimum for tranfection of these cells, which can be tricky when they grow quite fast.
In other cell lines lower cell confluence is recommended for tranfection efficiency. What I tend to do is set up a range of cell confluence or vector concentrations to find the best- it doesn't have to be a big range, one or 2 different cell densities or vector concentrations.
I knew it! I knew it! Well, not in the sense of having the slightest idea, but I knew there was something I didn't know.