Thanks for the note. I have always wondered with suspicion about
contransfections. Does this not introduce squelching and perhaps an
under-representation of the true promoter activity? I have seen some labs
not use an internal control plasmid but I think you're right if you say a
majority of labs do.
What I typically do is transfections in triplicate (6 well dishes) and I do
this at least 3 times. I am finding no significant difference between
experiments when I express the normalized RLUs (normailzed to protein) as a
percent of SV40 or as a fold increase over pGL3basic (which bythe way gives
high background in many cells!). I do not see any profound argument
against not using an interbnal standard although I can imagine some hostile
reviewers wanting one to do it the "correct way."
Is there really a correct way of expressing the data?
I would encourage more people to comment on this issue that I have debated
for some time know. I really do not know the answer.
The Love you take is equal to the Love you make--P. McCartney