PRODUCTION OF MOUSE MONOCLONAL-ANTIBODIES USING A CONTINUOUS CELL-CULTURE FERMENTER AND PROTEIN-G AFFINITY-CHROMATOGRAPHY

The production of anti-alpha-fetoprotein monoclonal antibodies for dia gnostic use was carried out in a stirred tank fermenter equipped with a double membrane stirrer for bubble free aeration and continuous medi um perfusion. A serum-free medium supplemented with 4 mM L-glutamine a nd 2.0 g/l glucose with a protein content of only 780 mu g/ml was used for the production process. The harvested antibodies were concentrate d 50-fold using a tangential ultrafiltration system and were then puri fied in a one step purification process by protein G affinity chromato graphy. The purity of the final product (90%) was controlled by SDS-po lyacrylamide gel electrophoresis, gel exclusion chromatography and iso electric focussing. For further quality controls of the product the im munoglobulin subclass and the isoelectric point were determined and th e specificity of the purified mAb was tested by RIA using I-125 labell ed alpha-fetoprotein. 1.87 g of purified monoclonal antibodies were pr oduced (90% purity) within 2 weeks. It was found that the use of this type of stirred tank fermenter combined with a one step purification p rocess using protein G affinity chromatography represents a suitable m ethod for the fast production of medium scale quantities (500 mg - 5 g ) of monoclonal antibodies for diagnostic use.