RNA transfection VS Plasmid DNA transfection - (Dec/24/2006 )

Dear all,
I am quite confused about transfection with in vitro synthesized RNA and transfection with plasmid DNA.
Since our final goal is to get the cell synthesize our aimed protein, when should we consider to transfect cells with in vitro synthesized RNA or plasmid DNA??
Thanks in advanced.

Making RNA from plasmid and then one has to take care that RNA is not getting degraded before transfecting cells (too many precautionary steps).

Compared to going thru all that stuff, I would simply transfect the plasmid. We get good protein production so y bother with the RNA

Some times for RNA viruses, we need to transfect cells with RNA as to get virus production, so we go thru the whole step with RNA.

I dont know abt going the RNA route for protein production.

You need to add 5' cap structure or the RNA may not express efficiently.

Generally there is no point to go through all the troubles using synthetic RNA as template. It is costly, time cosuming to make, very transient in nature and is error prone.

Besides RNA virus recombinantion, two possible uses for RNA-based transfection-translation are 1) you want to use cytoplasmic translation mechanism to study transfection process in cells to differentiate cytoplasm vs nuclear delivery rate limiting steps. For some cells, mRNA transfection performs better than DNA transfection because nuclear trafficking step present a real problem for plamsid to enter. 2) you want the protein, but dont want to have potential gene integrated to target cells. For example, you want to express transiently SV-40 large T protein, but you dont want this gene hang around for longer than needed, you use RNA. This has some values for immunological application, particulary in vivo situations.

Thanks a lot for your replies, Scolix and Genehunter-1. Now, I am clear and I have a decision for my new project.