title: Determination of dissolved CO(2) concentration and CO(2) production rate of mammalian cell suspension culture based on off-gas measurement.
abstract: The determination of dissolved CO(2) and HCO(3)(-) concentrations as well as the carbon dioxide production rate in mammalian cell suspension culture is attracting more and more attention since the effects on major cell properties, such as cell growth rate, product quality/production rate, intracellular pH and apoptosis, have been revealed. But the determination of these parameters by gas analysis is complicated by the solution/dissolution of carbon dioxide in the culture medium. This means that the carbon dioxide transfer rate (CTR; which can easily be calculated from off-gas measurement) is not necessarily equal to carbon dioxide production rate (CPR). In this paper, a mathematical method to utilize off-gas measurement and culture pH for cell suspension culture is presented. The method takes pH changes, buffer and medium characteristics that effect CO(2) mass transfer into account. These calculations, based on a profound set of equations, allow the determination of the respiratory activity of the cells, as well as the determination of dissolved CO(2), HCO(3)(-) and total dissolved carbonate. The method is illustrated by application to experimental data. The calculated dissolved CO(2) concentrations are compared with measurements from an electrochemical CO(2) probe.
authors.affiliation: Technische Universität Hamburg-Harburg, Bioprozess- und Bioverfahrenstechnik, Denickestrasse 15, 21071 Hamburg, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Frahm
authors.forename: Heinz-Christian
authors.initials: HC
authors.lastname: Blank
authors.forename: Peter
authors.initials: P
authors.lastname: Cornand
authors.forename: Wolfram
authors.initials: W
authors.lastname: Oelssner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Guth
authors.forename: Paul
authors.initials: P
authors.lastname: Lane
authors.forename: Axel
authors.initials: A
authors.lastname: Munack
authors.forename: Klaus
authors.initials: K
authors.lastname: Johannsen
authors.forename: Ralf
authors.initials: R
authors.lastname: Pörtner
mesh_terms: D000818:Animals; D019149:Bioreactors; D002245:Carbon Dioxide / Q000032:analysis* / Q000138:chemical synthesis* / Q000378:metabolism; D002460:Cell Line; D003198:Computer Simulation; D006825:Hybridomas / Q000378:metabolism; D008322:Mammals; D008954:Models, Biological; D008956:Models, Chemical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013535:Suspensions
chemical_list: D013535:Suspensions; D002245:Carbon Dioxide