CO3 / HCO3 content of the culture medium - (Mar/31/2005 )

For the buffering system should i also add CO2 into the medium or only NaHCO3 into the medium?



Thanks for any input.

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hi
usually, medium contains all required. For CO2/HCO3 buffering, it only comes from the 5% of CO2 in the air of the cell storer.

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What if the medium i buy does not have NaHCO3? Should i have to add NaHCO3 into it? I don't need to add CO2 because it comes from the 5% CO2 gass right?

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wow...
if you don't have NaHCO3 i don't think you'll get good buffering capacity. You're right, CO2 come from the 5%CO2 in the culture air. It is in equilibrium with the HCO3 in the media to esure a pH close to 7.2. I think you should add the NaHCO3 in your medium, or buy a "full" medium.
i use a dmem media from gibco and here is the formula in salts (from their website...)(MW concentration, mg/ml, and molarity, mM)

Calcium Chloride (CaCl2) (anhyd.)____111___200___ 1.80
Ferric Nitrate (Fe(NO3)3"9H2O)______404___0.1____0.000248
Magnesium Sulfate (MgSO4) (anhyd.)_120___97.67__0.814
Potassium Chloride (KCl)___________75____400___ 5.33
Sodium Bicarbonate (NaHCO3)______84____ 3700__ 44.05
Sodium Chloride (NaCl)____________58____6400___110.34
Sodium hosphate monobasic (NaH2PO4-H2O) 138 125 0.906

Good luck
fred

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