English
As a nutrient required for cell growth, the role of serum in cell culture is self-evident, and the quality and sterility of serum are also the keys to determining the success of the experiment. So, how to inactivate serum? This requires the use of media bottles.
Serum inactivation steps are as follows:
1. Select a bottle that is the same as the media bottle as the control bottle, pour the same volume of distilled water as the serum into the control bottle, and measure the temperature.
2. Temperature adjustment. Insert two mercury thermometers into the bottle of the control group and place them in the water bath. When the thermometer shows 56 degrees, adjust the temperature of the calibration water bath to 56 degrees.
3. Put the media bottle and the control bottle together in a water bath, adjust the temperature to 56 degrees, take a water bath for half an hour, divide the bottle after inactivation, do a sterile test, and store it at -70--20 degrees.
4. It is necessary to observe the color and transparency of the frozen serum. If the color is reddish or the color is lighter with precipitation, it indicates that the quality of the serum is not good. Therefore, it is necessary to select a good quality serum for inactivation.
5. The use of serum should avoid repeated thawing, which will increase the probability of serum contamination and reduce the quality of serum. Once the repeatedly thawed serum is precipitated, it means that the serum is unavailable or of extremely poor quality.
6. In order to ensure the stability of the experimental results, ensure that the serum should be shaken well when dividing the bottle, and then divide the bottle, and try to use the same serum to ensure the principle of uniform variables.
The above are the specific steps of serum inactivation using media bottles, but it is worth mentioning that in most cell cultures, heat inactivation of serum is not necessary. In many cases, heat inactivation does not improve cell growth, but instead destroys serum and increases precipitation. Unless the literature indicates that inactivated serum must be used for the cells, the serum heat inactivation step can generally be omitted for cell culture.
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.