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Spiking based Raman Model Calibration for Perfusion Cell Culture using a Harvest Library
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  • Patrick Romann,
  • Jakub Kolar,
  • Daniela Tobler,
  • Christoph Herwig,
  • Jean-Marc Bielser,
  • Thomas Villiger
Patrick Romann
Hochschule fur Life Sciences FHNW

Corresponding Author:[email protected]

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Jakub Kolar
Hochschule fur Life Sciences FHNW
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Daniela Tobler
Hochschule fur Life Sciences FHNW
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Christoph Herwig
Technische Universitat Wien Forschungsbereich Bioverfahrenstechnik
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Jean-Marc Bielser
Merck KGaA
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Thomas Villiger
Hochschule fur Life Sciences FHNW
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Raman spectroscopy has gained popularity to monitor multiple process indicators simultaneously in biopharmaceutical processes. However, robust and specific model calibration remains a challenge due to insufficient analyte variability to train the models and high cross-correlation of various media components and artefacts throughout the process. Therefore, a systematic Raman calibration workflow for perfusion processes enabling highly specific and fast model calibration was developed. A harvest library consisting of frozen harvest samples from multiple CHO cell culture bioreactors collected at different process times was established, capturing process variability as widely as possible. Model calibration was subsequently performed in an offline setup using a flow cell by spiking process harvest with various sugars known to modulate glycosylation patterns of monoclonal antibodies. In a screening phase, Raman spectroscopy was proven capable not only to distinguish glucose, raffinose, galactose, mannose, and fructose in perfusion harvest, but also to quantify them independently in process relevant concentrations. In a second phase, a robust and highly specific calibration model for simultaneous glucose (RMSEP = 0.32 g/L) and raffinose (RMSEP = 0.17 g/L) real-time monitoring was generated and verified in a third phase during a perfusion process. The proposed offline calibration workflow allowed proper Raman peak decoupling, reduced calibration time from months down to days and can potentially be applied to other analytes of interest including lactate, ammonia, amino acids, or product titer.
12 Apr 2022Submitted to Biotechnology Journal
21 Apr 2022Submission Checks Completed
21 Apr 2022Assigned to Editor
17 May 2022Reviewer(s) Assigned
20 Jun 2022Editorial Decision: Revise Major
12 Jul 20221st Revision Received
15 Jul 2022Submission Checks Completed
15 Jul 2022Assigned to Editor
15 Jul 2022Reviewer(s) Assigned
26 Jul 2022Editorial Decision: Accept