CALCIUM ALGINATE IMMOBILIZED HYBRIDOMAS GROWN USING A FLUIDIZED-BED PERFUSION SYSTEM WITH A PROTEIN-FREE MEDIUM

Hybridoma SPO1 cells were immobilized in calcium alginate beads and we re further grown in a fluidized-bed perfusion system with a protein-fr ee medium. The presence of serum in the steps of entrapment was shown to be helpful for the preservation of cell viability. Each step during immobilization was investigated with respect to the extent of cell da mage caused. The immobilization process using small beads caused a low er cell viability initially but allowed a higher rate of cell growth s ubsequently, compared to those in large beads. In a perfusion system f or the continuous production of monoclonal antibodies (MAb), the viabl e cell density reached 2 x 10(7) cells per ml of beads with a viabilit y of 40%. Compared with the cells in suspension culture, the immobiliz ed SPO1 cells showed higher viable cell based specific rates of substr ate uptake (glucose and glutamine) and of MAb production. A significan t drop in the formation of lactate after the cell growth entered a ste ady state suggested a higher activity of the Tricarboxylic Acid Cycle in the cells when the cell density became high.