Analysis of the reasons for the rapid drop of the pH of the culture medium in the cell culture flask

 Cell growth requires a suitable pH, most of which is 7.2-7.4, if it deviates from this range, it will have adverse effects on cells. Sometimes we will encounter the situation that the pH of the culture medium in the cell culture flask drops too fast. What is the reason for this?

Usually when cells grow very fast, the pH usually drops very fast. At this time, it can be solved by timely passage, increasing the passage ratio or reducing the serum volume. In addition, if the lid of the cell culture flask is tightened too tightly, the buffer capacity of the NaHCO3 buffer system is insufficient, the salt concentration in the culture medium is incorrect, and bacterial, yeast or fungal contamination can also cause the pH value to drop quickly. The following methods operate:

            FuDau T25 Cell Culture Flasks

1. Increase or decrease the CO2 concentration in the incubator according to the NaHCO3 concentration in the culture medium. The NaHCO3 concentration of 2.0g/L to 3.7g/L corresponds to the CO2 concentration of 5% to 10%.

2. Switch to a CO2-independent medium.

3. Loosen the cap 1/4 turn. Add HEPES buffer to a final concentration of 10 to 25 mM.

4. Use the medium prepared based on Earle's salt in the CO2 culture environment, and change the medium prepared with Hanks salt in the atmosphere culture environment.

            FuDau T75 Cell Culture Flasks

5. If it is caused by pollution, discard the culture and move it to the outside of the cell culture area as soon as possible. After the culture is treated with a strong oxidant such as 84, pour it into the pool, or sterilize it with antibiotics.

In a word, if the pH value of the culture medium in the cell culture flask drops too fast, the reasons may be various, and it is convenient to adopt the corresponding treatment method after finding out the specific reasons.