HEK293 Medium, What pH? - (Jan/29/2007 )

Hi. I just want to ask what pH you use with HEK293 (WT and transfected)?

I was given a protocol that added some NaOH (1M) 0.3ml in 100ml for WT and 0.5ml for trasnfected. Does anyone use this additional NaOH?

First, I started to do it but after finding out that most people didn't use it I decided not to. After a couple of weeks testing if they were OK I could notice any difference in cell grow or shape. Now many weeks later my WT doesn't look good although I think it may be some kind of contamination.

I also read in a previous post the importance of using good quality FCS. I'm currently using FBS instead of FCS and they don't look very bad to me. Should I use FCS? Why?

Could you share your experiences in these aspects? Any reasons why I should use additional NaOH or not?

Thanks

I use DMEM - 10% FBS, L-Gln, 1% Pen/Strep for all HEK 293. During transfection, I make media without the antibiotics ( DMEM, 10% FBS, L-GLn). But change the media back to nrmal one after 12 hrs.

I dont make any other special changes to the media for the HEK cells.

Thanks Scolix. I saw your medium composition in the previous post I mentioned. I use medium pretty much like yourself. Do you see any reason in using FCS instead of FBS or to add more NaOH? I suppose if some people are doing that way must be based on something.

well i though it was Hepes KOH wich was used for increasing the pH (especially in Joklik's medium)?
pH shoud be ranging from 6.8 to 7.4 better at 7.2