DMEM or EMEM Does it matter? (HeLa Cells & Transfection) - (Oct/11/2012 )
Hey guys, I was just off looking at ATCC and some of my old protocols (over a year ago) and I they all said that growth medium for Helas is MEM.
I recently got a new batch of Hela cells from a colleague and stupidly I used DMEM when I split them. They are growing fine and well.
Some background on the experiment: I'll be transfecting a plasmid that I created to test promoter activity using luciferase assays. As I mentioned, I have done this before over a year ago (but back then I used MEM)
1) I know the difference between DMEM and EMEM, what I am curious is does it affect the growth of cells in anyway i.e. it will gow faster in DMEM? Is DMEM more "potent" than EMEM since it has more nutrients?
2) If I had used MEM instead of DMEM during the transfections, will I get different results because of the different medium?
3) Should I make the switch back to MEM and how do I go about doing it?
4) Same situation for HepG2 cells although no transfection is being done. Different papers use DMEM but says use MEM. Will it matter which I use?
Thanks guys! Appreciate it!
besides i dont think that there should be any difference in the results when you use different mediums yes your transfection efficiencies might differ, but once you have had successful transfection i dont think the results would change. if the current experiment is part of a larger study where you have mostly used EMEM, then I would definitely suggest to change it back to EMEM. It could save you a bit of embarrassment if somebody asks why you changed the media ? though it shouldnt really matter, but scientists are skeptical by nature.
The only way i can think of switching back to MEM is to probably mix DMEM and MEM and gradually increase the ratio to 100% MEM. If you have old stocks you could try to bring that up in MEM.
I have shifted media before, from RPMI-1640 to EMEM. You simply shift to different media when u split the cells later, perhaps put lesser cells to allocate more production of new cells in the flask.
And yes, I did not see difference in cell growth between RPMI and EMEM either (RPMI is very similar to DMEM). But since ATCC suggested EMEM, and i did not manage to find any papers to support the use of RPMI on that cells, I figure it's safer to grow the cells back to EMEM so to avoid any problems with the reviewers and examiners.
I think it depends strongly on the cell line that you're using. For instance, a co-worker of mine sees very different results when she cultures her C2C12 cells on DMEM + L-Glutamine or DMEM + GlutaMAX. I've experienced this with my PC12 cell line, which are semi-adherent by nature in RPMI1640 but will adhere to the culture surface if grown in DMEM (this is caused by the calcium in DMEM, I've been told).
I've also been told by our lab head that some cell lines can take up to a month to fully get used to a change in medium. I'd advise you monitor your cells closely and, if possible, check for any variations in the controls in your data.