How long DNA and siRNA stay in transfected cells - (Mar/01/2006 )

Hi guys,
I wounder if anybody has an idea how long DNA or siRNA nucleotides stay inside cells after transfection before the cells get rid of them. I couldn't find any study about that in PubMed. Any idea or any reference will be very helpfull.
Thank you.

Hi emouad!

I assume you're talking about transient transfections?!

I haven't found a study to this question neither. But I think the main problem is not "loosing" the DNA but diluting. Your cells continue dividing after transfection but don't replicate the DNA, so after some time you have more cells without your DNA in the dish than with it. The time curve depends on the cell type you use (how fast the divide).
In my experiences with mouse ES-cells after 2 days it was still ok, but I never looked later on.

I think you'll have to test it out for your conditions.

Good luck,
Christiane

Thanks Christiane,
Yes I'm talking about transient transfection. But I heard that cells consider the DNA or siRNA as a stranger and get rid of it after 3 to 4 days. This is important for me because we want to transfect cells with As DNA against a certain mRNA which is not present in other cells and we want to know how long the DNA will stay when it's attached to a probe and how long it stays if it's free. Maybe we need to do a time dep. exp.