Comparison of domestic and imported bovine sera in promoting Vero cell growth

Objective To screen domestic bovine serum for replacement of imported serum used for Vero cell culture in rotavirus vaccine production through comparing the cell growth promoted by domestic and imported bovine sera. Methods Three batches domestic fetal bovine sera and one batch domestic new-born calf serum were evaluated. One batch imported fetal bovine serum was used as control. The cell culture medium was separately prepared with the above bovine sera. Vero cells were sequentially cultured in T175 flask and 2-layer cell factory, 3 passages each. Culture supernatant, cell morphology, and cell confluence of each passage were observed. Cell yield and relative growth rate compared to the imported serum were calculated. The cell yield was compared with the required cell output (T flask: >1.50×107 cells/ml; cell factory: >3.00×108 cells/ml) by single-sample t-test. The approximation degree of cell growth activity promoted by the domestic and imported sera was judged according to the cell relative growth rate. Results The growth status of all Vero cells cultured in domestic serum was good. When the cells were cultured in T flask, the range of cell yields was (1.56-9.30)×107 cells/ml, significantly different from the required cell output (t=2.44-3.76, P 0, indicating meeting the production requirement. The cell relative growth rates approached or exceeded 100%. When the cells were cultured in cell factory, there was no significant difference between the cell yield 〔(1.80-4.92)×108 cells/ml〕 in domestic serum group and the required cell output (t=-0.23-1.16, P>0.05). But the mean cell yields of only one batch fetal bovine serum and new-born calf serum were >3.00×108 cells/ml, and their cell relative growth rates were >90%. Conclusion When compared with imported serum, one batch bovine serum and one batch new-born calf serum can replace the imported serum for the use of Vero cell culture in the rotavirus vaccine production. Key words: Vero cells; Cell culture techniques; Bovine serum