title: A dual near-infrared and dielectric spectroscopies strategy to monitor populations of Chinese hamster ovary cells in bioreactor.
abstract: OBJECTIVE
  to develop a new strategy combining near-infrared (NIR) and dielectric spectroscopies for real-time monitoring and in-depth characterizing populations of Chinese hamster ovary cells throughout cultures performed in bioreactors.
  
  
  RESULTS
  Spectral data processing was based on off-line analyses of the cells, including trypan blue exclusion method, and lactate dehydrogenase activity (LDH). Viable cell density showed a linear correlation with permittivity up to 6 × 10(6) cells ml(-1), while a logarithmic correlation was found between non-lysed dead cell density and conductivity up to 10(7) cells ml(-1). Additionally, partial least square technique was used to develop a calibration model of the supernatant LDH activity based on online NIR spectra with a RMSEC of 55 U l(-1). Considering the LDH content of viable cells measured to be 110 U per 10(9) cells, the lysed dead cell density could be then estimated. These calibration models provided real-time prediction accuracy (R(2) ≥ 0.95) for the three types of cell populations.
  
  
  CONCLUSIONS
  The high potential of a dual spectroscopy strategy to enhance the online bioprocesses characterization is demonstrated since it allows the simultaneous determination of viable, dead and lysed cell populations in real time.
authors.affiliation: Laboratoire Réaction et Génie des Procédés, UMR 7274, CNRS-Université de Lorraine, 2 avenue Forêt de Haye, TSA 40602, 54518, Vandœuvre-Lès-Nancy, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Courtès
authors.affiliation: Laboratoire Réaction et Génie des Procédés, UMR 7274, CNRS-Université de Lorraine, 2 avenue Forêt de Haye, TSA 40602, 54518, Vandœuvre-Lès-Nancy, France. bruno.ebel@univ-lorraine.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ebel
authors.affiliation: Laboratoire Réaction et Génie des Procédés, UMR 7274, CNRS-Université de Lorraine, 2 avenue Forêt de Haye, TSA 40602, 54518, Vandœuvre-Lès-Nancy, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guédon
authors.affiliation: Laboratoire Réaction et Génie des Procédés, UMR 7274, CNRS-Université de Lorraine, 2 avenue Forêt de Haye, TSA 40602, 54518, Vandœuvre-Lès-Nancy, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Marc
mesh_terms: D000818:Animals; D019149:Bioreactors; D016466:CHO Cells / Q000502:physiology*; D049109:Cell Proliferation; D002470:Cell Survival; D003412:Cricetulus; D013057:Spectrum Analysis / Q000379:methods*
keywords: Chinese hamster ovary cells; Dielectric spectroscopy; Lactate dehydrogenase; Near-infrared spectroscopy; Online sensors; Process analytical technology; Real time monitoring