title: Dialysis cultures with immobilized hybridoma cells for effective production of monoclonal antibodies.
abstract: An industrial scale reactor concept for continuous cultivation of immobilized animal cells (e.g. hybridoma cells) in a radial-flow fixed bed is presented, where low molecular weight metabolites are removed via dialysis membrane and high molecular products (e.g. monoclonal antibodies) are enriched. In a new "nutrient-split" feeding strategy concentrated medium is fed directly to the fixed bed unit, whereas a buffer solution is used as dialysis fluid. This feeding strategy was investigated in a laboratory scale reactor with hybridoma cells for production of monoclonal antibodies. A steady state monoclonal antibody concentration of 478 mg l(-1) was reached, appr. 15 times more compared to the concentration reached in chemostat cultures with suspended cells. Glucose and glutamine were used up to 98%. The experiments were described successfully with a kinetic model for immobilized growing cells. Conclusions were drawn for scale-up and design of the large scale system.
  
  
  BACKGROUND
  c(Glc) - glucose concentration, mmol l(-1); c(Gln) - glutamine concentration, mmol l(-1); c(Amm) - ammonia concentration, mmol l(-1); c(Lac) - lactate concentration, mmol l(-1); c(MAb) - MAb concentration, mg l(-1); D - dilution rate, d(-1); D(i) - dilution rate in the inner chamber of the membrane dialysis reactor, d(-1); D(0) - dilution rate in the outer chamber of the membrane dialysis reactor, d(-1); q*(FB,Glc) - volume specific glucose uptake rate related to the fixed bed volume, mmol l(FB)           (-1) h(-1); q*(FB,Gln) - volume specific glutamine uptake rate related to the fixed bed volume, mmol l(FB)           (-1) h(-1).
authors.affiliation: Technische Universität Hamburg-Harburg, Bioprozeß- und Bioverfahrenstechnik, Denickestr. 15, 21071, Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Pörtner
authors.forename: I
authors.initials: I
authors.lastname: Lüdemann
authors.forename: H
authors.initials: H
authors.lastname: Märkl