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

Mon Aug 01 10:45:51 CST 2022

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:

cell culture flask

            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.

cell culture flask

            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.

The FAI climbed 5.9 percent year-on-year in the first 11 months of 2018, quickening from the 5.7-percent growth in Jan-Oct, the National Bureau of Statistics (NBS) said Friday in an online statement.

The key indicator of investment, dubbed a major growth driver, hit the bottom in August and has since started to rebound steadily.

In the face of emerging economic challenges home and abroad, China has stepped up efforts to stabilize investment, in particular rolling out measures to motivate private investors and channel funds into infrastructure.

Friday's data showed private investment, accounting for more than 60 percent of the total FAI, expanded by a brisk 8.7 percent.

NBS spokesperson Mao Shengyong said funds into weak economic links registered rapid increases as investment in environmental protection and agriculture jumped 42 percent and 12.5 percent respectively, much faster than the average.

In breakdown, investment in high-tech and equipment manufacturing remained vigorous with 16.1-percent and 11.6-percent increases respectively in the first 11 months. Infrastructure investment gained 3.7 percent, staying flat. Investment in property development rose 9.7 percent, also unchanged.