Optimization of growth of reconstructed CHO cells and expression of its product EPO

Objective To explore the optimal pH value for over-expression of erythropoietin with high level of sialic acidification.Methods The effects of different pH values on cell growth,yield of EPO,and content of EPO sialic acid were obserred.Results Level of EPO expression could reach 10 388 IU/ml,sialic acid up to 11.5 mol/molEPO,and purification yield up to 17.9％ as the pH value was between 7.10 to 7.25.Conclusions 7.10 to 7.25 can be the optimal pH value by a comprehensive assessment of the factors of level of cell maintenance,expression of EPO,purification yield,and sialic acid content,which provides a basis for optimization of the industrial production of EPO. Key words: pH; CHO cells; Erythropoietin; Cell culture