Hydroxyethyl piperazine ethanesulfonic acid HEPES and sodium bicarbonate for cell preservation solution
Hydroxyethyl piperazine ethanesulfonic acid HEPES is usually paired with sodium bicarbonate and used as a buffer system in cell preservation solution or cell culture solution. In the non-inactivated virus nucleic acid preservation solution that requires cell culture, it also contains HEPES components. Hanks cell culture medium.
The dissociation constant of hydroxyethyl piperazine ethanesulfonic acid HEPES is 7.5, and the buffer range is 6.8-8.2. The pH required for most cells is also 7.2-7.4. The optimum pH for some cell cultures can reach 7.0 and 7.7, both It is in the suitable buffer range of HEPES, which is very suitable for the cultivation of most cells.
Desheng specializes in the production of HEPES
In the cells of organisms, the most important buffer system is bicarbonate and carbon dioxide to maintain the normal pH value of life activities and cell metabolism, so most cell culture solutions also rely on bicarbonate (usually sodium bicarbonate) and CO2 The system is buffered.
While CO2 is unstable in solution, the concentration of CO2 in the gas phase should be in equilibrium with the concentration of sodium bicarbonate in the culture solution. If the CO2 concentration in the gas phase or in the incubator air is set at 5%, the addition amount of NaHCO3 in the culture solution is 1.97g/L; if the CO2 concentration is maintained at 10%, the addition amount of NaHCO3 in the culture solution is 3.95g/L. Moreover, cell culture flasks or other containers should not be sealed too tightly to ensure CO2 gas exchange. The stability of bicarbonate is not very good. When stored for a long time or when the temperature rises, CO2 will be emitted and escape with the air, which will increase the pH of the system.
When culturing or observing cells in open mode, adding 10-25mM HEPES to the sodium bicarbonate buffer system can alleviate the problem of too rapid changes in the pH of the solution and maintain a relatively constant pH value of the culture solution. HEPES is much more expensive than carbonate buffer. In principle, it can completely replace bicarbonate. When the environmental CO2 concentration is not high enough, bicarbonate will hydrolyze in the alkaline direction and increase the pH.
In actual cell culture, it is not good to only use HEPES without NaHCO3. Bicarbonate and dissolved CO2 are also very important for good cell growth; and HEPES will increase the osmotic pressure of the cell culture system to a certain extent. When the concentration is too high, there may be some cytotoxicity.
It can be seen that both HEPES and NaHCO3 are buffers in the cell culture medium and have their own advantages and functions. Among them, Desheng produces high-quality HEPES raw materials and can configure the solution by itself. The non-toxic side effects of HEPES on cells are not absolute, and the recommended concentration is 10-50mmol/L.
HEPES, as a zwitterionic buffer, increases the osmotic pressure of the cell culture system by increasing the concentration of solution ions, maintaining normal cell morphology and function, and improving cell survival rate. Widely used in cell culture, especially under specific conditions such as tumor cell culture, it is crucial to maintain cell growth and function.