In-situmicroscopy and 2D fluorescence spectroscopy as online methods for monitoring CHO cells during cultivation

Bonk, Sophia; Sandor, M.; Rüdinger, F.; Tscheschke, Bernd; Prediger, Andreas; Babitzky, Alexander; Solle, Dörte; Beutel, Sascha; Scheper, Thomas

doi:10.1186/1753-6561-5-s8-p76

Cited by 11 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the investigated process parameter, the RMSE of each parameter was determined and they are summarized in Supporting information, Table S1. Also, all RMSEs are comparable with the values achieved by PLS models in large-scale stirred bioreactors [37,38]. These findings confirm the reliability of the new measurement system and the good quality of the models developed based on the measured multiwavelength (2D) fluorescence spectra.…”

Section: Bioprocess Monitoring By Multi-wavelength (2d) Fluorescence supporting

confidence: 79%

“…Predictions with a R 2 of 0.88 for glucose and a R 2 of 0.53 for biomass estimation were achieved due to evaluations of multi‐wavelength (2D) fluorescence data of S. cerevisiae culture broths (3.5 L and 20 L bioreactors) . Better correlation coefficients were realized in CHO cultures (2.5 L bioreactor) for estimations of glucose ( R 2 = 0.97), lactate ( R 2 = 0.97) and glutamate ( R 2 = 0.98) . All studies mentioned above applied PLS models for the determinations.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Parallel online multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate

Ladner

Beckers

Hitzmann

et al. 2016

Biotechnology Journal

View full text Add to dashboard Cite

Small-scale high-throughput screening devices are becoming increasingly important in bioprocess development. Conventional dipping probes for process monitoring are often too large to be used in these devices. Thus, optical measurements are often the method of choice. Even some parameters that cannot directly be measured by fluorescence become accessible via sensitive fluorescence dyes. However, not all compounds of interest are measurable by this technique. Recent studies applying multi-wavelength (2D) fluorescence spectroscopy in combination with chemometrics have shown that information on numerous analytes is obscured by the fluorescence data. Hitherto, this measurement technique has only been available on the scale of stirred tank fermenters. This work introduces a new device for multi-wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate. Using a combination of spectrograph and CCD detector, the required time per measurement cycle in a 48-well microtiter plate was 0.5 h. Cultures of Hansenula polymorpha and Escherichia coli are monitored. The concentrations of glycerol, glucose and acetate as well as pH are determined using partial least square (PLS) models. Because a pH-sensitive fluorescence dye was not required, no dependency of the pK of a fluorescence dye exists, and measurements in the low pH range can be obtained.

show abstract

Section: Bioprocess Monitoring By Multi-wavelength (2d) Fluorescence supporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Parallel online multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate

Ladner

Beckers

Hitzmann

et al. 2016

Biotechnology Journal

View full text Add to dashboard Cite

show abstract

“…A photodiode is used to record the intensities for the 120 filter combinations, resulting in 2D spectra with an excitation wavelength ( λ ex ) range between 290 and 550 nm and an emission wavelength ( λ em ) range between 310 and 590 nm (Marose et al, 1998). In combination with methods of multivariate data analysis (MVDA), the spectroscopic setup has successfully been applied for the monitoring and control of various microbial and eukaryotic cultivation processes for nearly 25 years (Bayer et al, 2020; Bonk et al, 2011; Haack et al, 2007; Johansson & Liden, 2006; Ödman et al, 2010; Skibsted et al, 2001). In a more recent 2D fluorescence monitoring system for stirred tank reactors, the continuous xenon lamp was replaced by three separate high‐power LEDs at λ ex of 280, 365, and 455 nm.…”

Section: Introductionmentioning

confidence: 99%

Advancing 2D fluorescence online monitoring in microtiter plates by separating scattered light and fluorescence measurement, using a tunable emission monochromator

Berg,

Busch,

Alawiyah

et al. 2023

Biotech & Bioengineering

View full text Add to dashboard Cite

Online fluorescence monitoring has become a key technology in modern bioprocess development, as it provides in‐depth process knowledge at comparably low costs. In particular, the technology is widely established for high‐throughput microbioreactor cultivation systems, due to its noninvasive character. For microtiter plates, previously also multi‐wavelength 2D fluorescence monitoring was developed. To overcome an observed limitation of fluorescence sensitivity, this study presents a modified spectroscopic setup, including a tunable emission monochromator. The new optical component enables the separation of the scattered and fluorescent light measurements, which allows for the adjustment of integration times of the charge‐coupled device detector. The resulting increased fluorescence sensitivity positively affected the performance of principal component analysis for spectral data of Escherichia coli batch cultivation experiments with varying sorbitol concentration supplementation. In direct comparison with spectral data recorded at short integration times, more biologically consistent signal dynamics were calculated. Furthermore, during partial least square regression for E. coli cultivation experiments with varying glucose concentrations, improved modeling performance was observed. Especially, for the growth‐uncoupled acetate concentration, a considerable improvement of the root‐mean‐square error from 0.25 to 0.17 g/L was achieved. In conclusion, the modified setup represents another important step in advancing 2D fluorescence monitoring in microtiter plates.

show abstract

“…The technique has among others been applied for monitoring cultivations of bacteria, 5–7 filamentous fungi, 8,9 yeast 10,11 and mammalian cells. 12,13 In such cultivation processes pH is normally controlled and kept constant at a set-point value. In contrast, in food fermentations such as yoghurt 14,15 and sourdough production, 16 pH is changing during the fermentation time as a function of the biological process.…”

Section: Introductionmentioning

confidence: 99%

Weighted PARAFAC and Nonlinear Regression for Handling Intensity Changes in Fluorescence Spectroscopy Caused by pH Fluctuations

2016

View full text Add to dashboard Cite

Fluorescence spectroscopy is a sensitive and selective technique, which can be of great value in bioprocesses to provide online, real-time measures of chemical compounds. Although fluorescence spectroscopy is a widely studied method, not much attention has been given to issues concerning intensity variations in the fluorescence landscapes due to pH fluctuations. This study elucidates how pH fluctuations cause intensity changes in fluorescence measurements and thereby decreases the quality of the subsequent quantification. A photo-degradation process of riboflavin was investigated by fluorescence spectroscopy and used as a model system. A two-step modeling approach, combining weighted PARAllel FACtor analysis (PARAFAC) with weighted non-linear regression of the known reaction kinetics, is suggested as a way of handling the fluorescence intensity shifts caused by the pH changes. The suggested strategy makes it possible to compensate for uncertainties in the shifted data and thereby obtain more reliable concentration profiles for the chemical compounds and kinetic parameters of the reaction.

show abstract

In-situmicroscopy and 2D fluorescence spectroscopy as online methods for monitoring CHO cells during cultivation

Cited by 11 publications

References 0 publications

Parallel online multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate

Parallel online multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate

Advancing 2D fluorescence online monitoring in microtiter plates by separating scattered light and fluorescence measurement, using a tunable emission monochromator

Weighted PARAFAC and Nonlinear Regression for Handling Intensity Changes in Fluorescence Spectroscopy Caused by pH Fluctuations

Contact Info

Product

Resources

About