Duration of cell line transfected - (Oct/26/2005 )

I heard that when you transfect your plasmid into a cell line, this cell line continues the transcription of this new sequence indefinitely. I wonder: Is this true? Is there no degradation of this new mRNA? How many weeks or flask transferred could last until the experiments performed with this cell line are not longer reliable?

Are the expression patterns also constant? I mean, if you get a determinated number of proteins in the cell membrane this number will decrease which each generation?

Sorry if my questions are too basic, I am just starting.

Thank you for help with your expertise.

hi
if the cell considers it as little poisoning, it may methylate DNA (including the promoter) leading to inactivation of your gene...

I think the main issue with sustained expression in this case is the retention of the transfected DNA. In many cases, researcher will include a selectable drug resistance marker in the transfected DNA to enable selection of cells with sustained expression. It appears that in this population, the DNA construct will non-specifically integrate into the chromosome of the cells and be passed on in subsequent cell division cycles. This is usually termed a "stable" transfection of the host cells. If a gene is toxic, it maybe difficult to get stable clones and thus a transient transfection is a viable aternative.