I'm transfecting DNA plasmids into HEK293 cells with invitrogen lipofectamine 2000.
In last summer, my cells went well with low glucose DMEM and 5% CO2. From this year, our lab changed whole HEK293 cell culture system. We used 11995-high glucose DMEM along with 8% CO2 to grow the cells, and started using Opti-MEM or 11995 free medium to transfect DNA. My cells can grow well with the high glucose DMEM and 8%CO2 W/O transfection. But neither of the Opti-MEM and high glucose DMEM can keep my cells living after transfection with them.
Does anybody have any ideas about this kind of trouble?
Thanks a lot!