"Robert Hartley" <rh at mblab.gla.ac.uk> wrote in message
news:rh-1601011002080001 at a6-curtis.ibls.gla.ac.uk...
> In article <3A640393.8B8B6B42 at unav.es>, joses at meseta.unav.es (Juan
> =?iso-8859-1?Q?Os=E9s?=) wrote:
>> > Hi !
> > I would like to know why you have to add 5% of CO2 in cell cultures. It
> > is used in all protocols I have read.
>> It keeps the pH correct in Eagles Bicarbonate buffered systems for eg.
>> For a look at different culture media constituents get a copy of the Life
> technologies cell culture catalogue.
> You don't always have to use CO2, EG endothelial cultures that I grow in
> HEPES buffered media.
maybe a few remarks :
1) 5% CO2 works for most media like MEM
if there is more bicarbonate , DMEM ,we use 8% CO2
if there is less , MCDB153 , KGM , some experimental
media , we try 3%
2) zero CO2 , only hepes , will have other effects
as bicarbonate is a cell metabolyte and actively
transported in (some) cells
Am J Physiol Renal Physiol 2000 Jul;279(1):F24-45
A mathematical model of the outer medullary collecting duct of the rat.
Pflugers Arch 1999 Aug;438(3):322-9
Stoichiometry of the rat kidney Na+-HCO3- cotransporter
expressed in Xenopus laevis oocytes.
Am J Physiol 1997 May;272(5 Pt 2):R1379-89
Effects of A-23187 and verapamil on the active transport
enzymes in turtle bladder epithelial cells.
3) hepes is converted to a toxic substance by day light
So hepes is not only good news.