CV1 transfection using Lipofectamine 2000

Hi,
I'm working with African green monkey CV-1 cells and it is hard to transfect them. I used Invitrogen pBudCE4.1 vectors to clone my genes and had problems with transfection. I tried Fermentas and Roche transfection kits. Then, I ordered Lipofectamine 2000. I know it is highly efficient. I optimized it with a vector coding GFP. But now, I have problems with my transfection using pBudCE4.1 vector. My transfected cells died in a day. I tried it again, but the result is the same. Anyone using Lipofectamine 2000, or working with CV1 cells to help me?
Thanks in advance,
Burcu

I have been having a similar problem with lipofectamine 2000 and CV-1 cells. Changing the media after 4-5 h following transfection greatly reduced the cell death for me, but did not help with poor transfection efficiency.

I got high transfection efficiency in CV-1 cells using Roche's Fugene 6 reagent (@ 3ul/ug DNA), but this is not meant to be used for co-transfection of plasmids and siRNA, which is what I need to do and why I am using lipo2000. If you are using just DNA, you may want to try Fugene.

Further questions:
How much DNA and lipofectamine 2000 are you using per well? (and what is your well size?)
Also, do you dilute in serum free media or opti-mem?
How many cells do you plate out and what is their density at time of transfection?

1.I'm using 6well plate and for each well I used 4ug DNA and 8ul lipofectamine as they indicated in their CV1 transfection protocol.
2.I use serum free ALPHA-MEM or ISCOVE-MEM medium.
3.My cell density is >90% at the time of transfection.

As you mentioned in your first reply that I also changed medium after 5-6 hours, it helped but not as much as I wanted. I also have a FuGENE trial from the company. When I was optimizing my CV1 cells with lipofectamine, I also tried it but lipofectamine gave higher efficiency. What was your transfection efficiency for both reagent, can you remember?
Thanks for your replies..