English
Serum refers to the colloidal liquid from plasma after removing fibrinogen, including fetal bovine serum, calf serum, adult bovine serum, and horse serum. Serum is generally stored in a dedicated media bottle and placed in a corresponding storage environment according to the type. Factors affecting serum quality include the following:
1. Endotoxin
The domestic standard is not higher than 5EU/ml. Endotoxin is a component of the cell wall after the bacteria are broken, so the level of endotoxin content can show the aseptic operation in a series of processes from blood collection to production. If the endotoxin content is extremely high, it indicates that the serum has been contaminated.
2. Total protein content
The general range of fetal bovine serum is 30-40mg/ml. If the value is too high, it means that the age of the ox was too old, not fetal bovine, and the value is too low, indicating that the serum may be mixed with water.
3. Hemoglobin
The standard is not higher than 20mg/dl, the redder the color, the higher the value, and vice versa, the lower the value.
4. pH
The domestic serum is mostly higher than 7.5, and the imported fetal bovine serum is mostly lower than 7.5. The specific reason is unknown and may be related to the age of the cow. This can also be used to initially identify the source of the serum.
5. Microorganisms
Including bacteria, molds, mycoplasma, bacteriophages, various pathogenic viruses, etc. Among them, Escherichia coli has little effect on the quality of serum, and pathogenic viruses, especially BVDV, exist in almost 90% of domestic serum, and these microorganisms are the most important. One of the important factors of domestic serum quality.
The above is the influence of its own factors on the quality of the serum production process. In addition, the quality of the media bottle will also have a certain impact on the serum. If the media bottle is not tightly sealed or the sterilization is not complete, it will directly lead to the contamination of the serum. The application of the contaminated serum in the cell experiment will slow down or even stop the growth of the cells, which will affect the experimental effect.
Therefore, when selecting serum, while identifying the quality of the serum, pay attention to whether the seal of the media bottle is intact to ensure that the serum quality is good.
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.