why transfected cells has less RNA? - (May/24/2006 )

I transient transfected 2ug plasmid DNA into mammlian cells. I cultured cells for 7 days so that they can be confluence on 96 well plate. After that, I used trizol to extract RNA, and I got 78ng/ul RNA for transfected cells and 211ng/ul RNA for non-transfected control. I would thought that transfection gonna increase the genetic material in the cell not decrease it. So I don't understand why my transfected cells has less RNA?

A quick answer to your question is that transfected cells grow slower than untransfected control cells due to cytotoxicity, expression of transfected gene, etc. The increase in transcripts from transfected gene is neglectable.

i agree with pcrman.
Moreover, due to groing difficulties, the number of collected cells is often more important in non tranfected cells, giving an additionnal explanation to the difference in RNA global quantity.