Exploring the capabilities of fluorometric online monitoring on chinese hamster ovary cell cultivations producing a monoclonal antibody

Abstract

Online monitoring of Chinese hamster ovary fed-batch cell cultures via two-dimensional fluorescence spectroscopy (2DFS) was evaluated in this work. Particular attention was directed toward different process strategies regarding the use of nutrient-rich feed media and temperature shifts. These intentionally performed process manipulations broadened the variances in the obtained fluorescence spectra and this was suspected to hamper the generation of reliable soft sensors. Principal component analysis of the obtained fluorescence data showed that temperature shift and feeding strategy had a considerable impact on the fluorescence signals. Partial least square regression models were calculated for the prediction of glucose, lactate, monoclonal antibody (mAb), and viable cell concentrations (VCC). It was aimed to integrate all 2DFS datasets in the respective calibration models regardless of the process-strategy-dependent diversity. Contrary to the expectations, it was feasible to calibrate soft sensors for the online prediction of glucose (7 latent variables (LVs), Rcal2 = 0.97, rout mean squared error of prediction (RMSEP) = 1.1 g L ), lactate (5 LV; Rcal2 = 0.96; RMSEP = 0.5 g L ) and mAb concentrations (4 LV; Rcal2 = 0.99; RMSEP = 11.4 mg L ). Feeding and temperature shifts had the highest impact on the VCC model (3 LV; Rcal2 = 0.94; RMSEP 3.8 × 10 mL ), nevertheless the prediction of VCC from the fed-batch 2DFS data was feasible. The results strongly indicate that variances in the datasets due to the process strategy can be tolerated to some extent by the respective soft sensors. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1592-1600, 2016.

A novel LED‐based 2D‐fluorescence spectroscopy system for in‐line bioprocess monitoring of Chinese hamster ovary cell cultivations—Part II

“…Lactate does not influence fluorescence directly, therefore a quantitative correlation by PLS is not possible. Authors of other studies described a lactate correlation without causality . A closer study of the RFI shows that the wavelength region of the Rayleigh scattering stagnates during the lactate metabolic shift (Figure C).…”

“…A broad overview about many applications of fluorescence spectroscopy in bioprocess monitoring is given in the literature . 2D‐Fluorescence spectroscopy allows the measurement of several fluorophores simultaneously by using multiple combinations of excitation and emission wavelengths.…”

Towards robust cell culture processes — Unraveling the impact of media preparation by spectroscopic online monitoring

“…Data preprocessing of the 2D FL data was done by an in‐house code in order to remove scattering effects (e.g. Rayleigh scattering) and for background subtraction . All PCA and PLS models were established using SIMCA ® (Sartorius Stedim Biotech, Germany).…”

Hybrid Modelling and Multi- Parametric Control of Bioprocesses

“…Ohadi et al (2014) described that it is possible to predict key process parameters at-line in Chinese hamster ovary cell (CHO) shake flask cultures [10]. Schwab et al (2016) proved that it was possible to predict fluorescent and non-fluorescent key process parameters online in CHO fed-batch cultivations with highly fluorescent feed medium. So far, however, none of the existing studies have focused on online monitoring of product quality parameters during upstream processing (USP).…”