The components and proportions of pro-cytokines, pro-adhesion factors, IgG and other active substances contained in them were different. Imported and some domestic fetal bovine serum were collected through heart puncture, while some domestic fetal bovine serum was collected from fetal bovine blood within 8 hours after birth. After 18 months of screening blood sources, through a series of indicators and test controls, Cell-Box blood collection staff selected high-quality blood sources in China and abroad with extremely demanding standards and signed cooperation agreements. After each batch of serum is mixed in batches, it is made by fine filtration of 0.1um for 3 consecutive grades. After quantitative filling, it passes a series of index tests, a variety of cell culture tests, and processes that comply with international sterilization methods. Users can be assured to use, according to the requirements of different cell culture, they can choose different concentrations of 5%-20% confection, most of the cells of the serum concentration of 10%.