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Double Transfection problems? - (Oct/17/2005 )

Hello...I've been having problems with double transfections and am getting a little frustrated.

I have a small peptide coupled with CFP (~250 aa) and another gene with YFP thats about 1500 aa. When I try to do a double transfection I only see one or the other with fluorescence (I have appropriate dichroics).

Even more bizarre I have made a polyclonal cell line under selection pressure with the YFP vector. I try to transiently transfect the CFP and still the problem. 95% of the ones expressing YFP have no CFP. 95% of the cells expressing CFP have no YFP. There is a very small population that has both vectors at very very very small expression levels.

Any thoughts?

-DavidK-

QUOTE (DavidK @ Oct 17 2005, 03:01 AM)
Hello...I've been having problems with double transfections and am getting a little frustrated.

I have a small peptide coupled with CFP (~250 aa) and another gene with YFP thats about 1500 aa. When I try to do a double transfection I only see one or the other with fluorescence (I have appropriate dichroics).

Even more bizarre I have made a polyclonal cell line under selection pressure with the YFP vector. I try to transiently transfect the CFP and still the problem. 95% of the ones expressing YFP have no CFP. 95% of the cells expressing CFP have no YFP. There is a very small population that has both vectors at very very very small expression levels.

Any thoughts?

what abouth the promoter competition?

-Jusu-