My DMEM has 3.7g/L of Sodium bicarbonate, instead of 1.5g/L (I only have this DMEM), suggesting that my sensitive endothelial cells need 10% CO2 incubator. However I am working in an academic institution where the incubators are set at 5% CO2 for everyone. Therefore I want to add HEPES in my DMEM instead, and put in the 5% CO2 incubator. Do you think that this is a good idea?