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Abstract : |
The effects of osmotic pressure on the cell growth and Monoclonal antibody (MAb) production by hybridoma cells in static and agitated cultures were investigated. The preliminary studies in static cultures showed that the maximal total cell number reaching about 11.1x105 cells mL-1 was obtained in cultures of 375 mOsmol kg-1, while the maximal MAb production of 61 mg L-1 was obtained in cultures of 400 mOsmol kg-1. On transferring the cultivation process to agitated cultures in spinner flasks at high shear of 150 rpm, the maximal cell number was reduced to 8.4x105 cells mL-1. This was obtained in medium of osmotic pressure of 325 mOsmol kg-1. Further increase in medium osmolarity resulted in significant decrease in total cell number. On the other hand, the cultivation in spinner flask gave higher yield of MAb than static culture. The maximal concentration of MAb of 135 mg L-1 was obtained in medium of 375 mOsmol kg-1. Based on these data, an experiment was designed to increase the volumetric MAb production by shifting the medium osmolarity from 325 mOsmol kg-1 to 375 mOsmol kg-1 during the late exponential growth phase of cells. This resulted to an increase in MAb volumetric production reaching 165 mg L-1. This value is about 68% higher than those obtained in culture of constant osmolarity of 325 mOsmol kg-1. This value is also about 22% higher than the maximal volumetric MAb production obtained in culture of 375 mOsmol kg-1 adjusted from the beginning of cultivation time., |
