Serum is a kind of natural medium. As a nutrient for cell growth, serum provides cells with hormones, various growth factors, binding proteins, etc., and also plays a role in protecting cells. The quality of serum will directly affect the growth and metabolism of cells. When judging the quality of serum, do not ignore the tightness of the media bottle.
The quality of serum depends on three factors: one is the object of the material, the second is the process of sampling, and the third is the sealing of the media bottle. The animals used for material collection should be healthy and disease-free and within the specified birth days. The material collection process should be carried out in strict accordance with the operating procedures, and the prepared serum should be subject to strict quality identification. Requirements in the "Procedures for the production of biological products by in vitro culture of animal cells" published by WHO:
1. Bovine serum must come from a herd or country that is documented to be free of BSE. And should have an appropriate monitoring system.
2. Some countries also require bovine serum from herds that have not been fed ruminant protein.
3. It was demonstrated that the bovine serum used does not contain inhibitors to the vaccine virus produced.
4. Serum should be sterilized by filtration through a filter membrane to ensure sterility.
5. No bacterial, mold, mycoplasma and virus contamination, some countries require no bacteriophage contamination.
6. It has a good support for the reproduction of cells.
In addition, judging the quality of serum should also pay attention to the tightness of the media bottle. If the packaging is not well sealed, it is easy to cause the serum to be contaminated and deteriorated, so you should pay attention to this when purchasing serum.
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.