As per my knowledge, CO2 and the bicarbonate salt added form a buffer solution for the exact maintenace of pH required according to the media or the organism.
It is true that our blood contains CO2, usually around 40mmHg, which is close to 5%. The importance in mammalian cell culture is the same as in mammalian blood. The majority of CO2 exists in the blood in the form of bicarbonate (HCO3-) which acts as a pH buffer to allow for gas, nutrient and metabolites fluctuations without causing wild pH changes. By providing a 5% CO2 overlay in a cell culture process you are ensuring that you will roughly maintain 5% dissolved CO2 (HCO3-) in solution. As cells release CO2, lactate and other pH affecting ions the CO2 concentration in solution will deviate from 5% forcing CO2 into or out of the atmosphere to maintain the balance between the two. For more information on why these systems strive to reach equilibrium research "Henry's Law."
"Our body contains 5 % CO2. So when we are culturing the cells it's needed and moisture and pH is important for cell culture it will maintain the same"
Interestingly atmospheric CO2 was closer to intracellular when lunged animals first evolved. If you wanted to keep the dissolved CO2 in the medium at the same level of blood you could just add bicarbonate, keeping the atmospheric CO2 high is one step further and seems to me a tacit admission that higher environmental CO2 levels are beneficial per se for eukaryotic cells, allowing them to use more O2 through the Bohr effect.
what if the CO2 come over 7%? recently our incubator have trouble and change the CO2 level :(
For maintaining pH of the culturing media as in human blood also 5% is there to maintain pH, it combines with Water to form bicarbonate that dissociates to H+ and HCO3-.
Nimal Raveendran has provided the perfect answer to this question, every other answers revolve around his response.
5% CO2 for the cell culture is due to the concentration of sodium bicarbonate in the culture medium. For instance. 1.5 to 2.2 g/L sodium bicarbonate was use for majority of mammalian cell culture, 5% CO2 is set in an incubator.
Source: https://www.atcc.org/Global/FAQs/5/F/The%20sodium%20bicarbonate-carbon%20dioxide%20system-57.aspx
to maintain CO2 concentration and pH similar to those in mammalian blood and tissues
I found this article to be very relevant in this case. Enjoy the read!
https://www.phe-culturecollections.org.uk/news/ecacc-news/co2-concentration-and-ph-control-in-the-cell-culture-laboratory.aspx
CO2 is not a metabolic requirement for cell cultures, its purpose is to dissolve into cell culture medium where a small proportion of it reacts with water to form carbonic acid which in turn interacts with its conjugate base (the dissolved bicarbonate ions in the medium) to control a stable physiological pH through the bicarbonate buffering system. The amount of sodium bicarbonate (NaHCO3) in the medium dictates the amount of CO2 that should be used to maintain the pH. Physiological pH is generally considered to be in the range of 7.2 to 7.4 for normal tissues
5%CO2 is needed to buffer the system to ensure that the normal physiological pH is maintained for optimum cell growth. CO2 will react with water to form carbonate.
For related RG discussion; see:
https://www.researchgate.net/post/What_is_the_relation_between_pH_and_dissolved_oxygen_in_a_bioreactor_cell_culture
Hi,
The following article also may help especially the subsession ph changes.
Article Animal-cell culture media: History, characteristics, and cur...
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Cell Biology
- Culture Cells
- Cell Line