3 replies to this topic

[prof. moriarty]

hi, i'm using dmem with hepes added b/c i am culturing out of co2 incubator for about a week. most mediums with bicarbonate have a concentration of 3.7 g/L, which would mess up the pH since I'm not using co2. however, I'm going to make a final concentration of 1 g/L bicarbonate for nutritional purposes.

The basic question is: can I add the bicarbonate just as a powder to the liquid medium? Or do I need to dissolve it in something first and then add?

Sorry for the silly question, I'm new to cell culture.

Thanks!

[prof. moriarty]

I was on the Sigma website, and I noticed that you can get the bicarbonate solution (7.5% in water) pre made. Have any of you used this before? Any difference in performance between powder and liquid?

Thanks

[mdfenko]

bicarbonate solution is not very stable (over the long haul).

but, addition of powder may affect the pH of your medium.

you can prepare and adjust a solution of bicarbonate prior to addition to your medium or you can add powder and check and adjust the pH, as necessary (you may not be adding enough to have a significant effect).

[molgen]

The powder is not sterile.
Adding it can contaminate your medium.
I'd dissolve it first, sterilize it and then add it to the medium.