mouse embryonic fibroblasts: why sodium pyruvate in medium?

[GysdeJongh]

"Antonio" <Antonio.Sarikas from gmail.com> wrote in message 
news:1179435519.575291.78430 from h2g2000hsg.googlegroups.com...
> Why do you add sodium pyruvate to the DMEM?

Hi Antonio,
pyruvate is needed as a source of energy.

The man who invented the medium eventually came up with the substances that 
were (minimally) needed for growth of mouse fibroblasts ; pyruvate was just 
one of them (he guessed)

One of the difficulties of cell culture is the composition of the medium : 
substances don't dissolve , are unstable etc , etc

Here are a few choises
1) Buy or make the complete medium and store it in small aliquotes in -20 
degrees ; thaw right before use ; don't use more than a few freeze - thaw 
cycles (my choise)
2)Buy the DMEM complete solution , store it at 6 degrees and use it within a 
few weeks.
3)Buy the DMEM solution without glucose and pyruvate  , store it at 6 
degrees  and add glucose and pyruvate from a stock solution right before you 
use it. (These two are the main unstable ones in solution)
4)Buy the complete powder and now add the sodium bicarbonate after 
dissolving it because in a solid the bicarbonate is the problem but glucose 
and pyruvate are now stable.

hth
Gys