On-Line, Real-Time Measurements of Cellular Biomass using Dielectric Spectroscopy

Yardley, John Edmund; Kell, Douglas B.; Barrett, J. D.; Davey, Christopher L.

doi:10.1080/02648725.2000.10647986

Cited by 96 publications

(79 citation statements)

References 93 publications

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“…When an alternating electric field is applied to the cell suspension culture, the cell membranes act as small capacitors leading to a buildup of electrical charge (polarization). The overall capacitance is thereby dependent on the frequency of the alternating electric field (usually in the range 0.1-10 MHz), as well as the cell size, morphology and cell concentration [86]. For suspension cultures with a uniform cell size, this technique is appropriate for host cell quantification because there is a correlation between the recorded permittivity and cell number.…”

Section: Process Controlmentioning

confidence: 99%

Concepts for the Production of Viruses and Viral Vectors in Cell Cultures

Grein¹,

Weidner²,

Czermak³

2017

New Insights Into Cell Culture Technology

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The industrial-scale manufacturing of viruses or virus-like particles in cell culture is necessary for gene therapy and the treatment of cancer with oncolytic viruses. Complex multistep processes are required in both cases, but the low virus titers in batch cultures and the temperature sensitivity of the virus particles limit the production scale. To meet commercial and regulatory requirements, each process must be scalable and reproducible and must yield high virus titers. These requirements are met by establishing a cell culture process that matches the properties of the virus/host-cell system and by using serum-free cell culture medium. This chapter focuses on two case studies to consider the different aspects of process design, such as the reactor configuration and operational mode: the continuous production of retroviral pseudotype vectors in a retroviral packaging cell line and the production of oncolytic measles virus vectors for cancer therapy.

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Section: Process Controlmentioning

confidence: 99%

Concepts for the Production of Viruses and Viral Vectors in Cell Cultures

Grein¹,

Weidner²,

Czermak³

2017

New Insights Into Cell Culture Technology

View full text Add to dashboard Cite

show abstract

“…The overall capacitance of the suspension, observed over the so-called b-dispersion range of frequencies (typically between 3 and 10 MHz) is directly proportional to the total volume of viable cells affected by the field [15][16][17]. In addition, by collecting capacitance readings over the characteristic range of frequencies of the electrical current, observations can be made as to the size of the cells in the suspension [18,19].…”

Section: Introductionmentioning

confidence: 99%

“…The main disadvantages of these methods are the long measurement time needed to obtain acceptable sensitivity and the relatively expensive equipment. Finally, over the last few years, satisfactory results and enhanced in-situ applicability were achieved using dielectric spectroscopy [4,8,[13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Dabros

Dennewald

Currie

et al. 2008

Bioprocess Biosyst Eng

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This work evaluates three techniques of calibrating capacitance (dielectric) spectrometers used for on-line monitoring of biomass: modeling of cell properties using the theoretical Cole-Cole equation, linear regression of dual-frequency capacitance measurements on biomass concentration, and multivariate (PLS) modeling of scanning dielectric spectra. The performance and robustness of each technique is assessed during a sequence of validation batches in two experimental settings of differing signal noise. In more noisy conditions, the Cole-Cole model had significantly higher biomass concentration prediction errors than the linear and multivariate models. The PLS model was the most robust in handling signal noise. In less noisy conditions, the three models performed similarly. Estimates of the mean cell size were done additionally using the Cole-Cole and PLS models, the latter technique giving more satisfactory results.

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“…The dielectric properties of biological cells and their different components (cell wall, membranes and cytoplasm) were summarized by Markx and Davey [4]. Over the last couple of decades a lot of research was done on the impedance of cell suspensions, in which a relationship between capacitance and viable cell number was reported [5][6][7][8]. Fehrenbach et al [5] used online capacitive measurements for biomass estimation of Saccaromyces cerevisiae, Pitchia pastoris and Streptomyces virginiae in suspension culture.…”

Section: Introductionmentioning

confidence: 99%

Biomass measurement of living Lumbriculus variegatus with impedance spectroscopy

Sammer¹,

Laarhoven²,

Mejias

et al. 2014

Journal of Electrical Bioimpedance

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Impedance spectroscopy is a useful tool for non-invasive and real time measurements of cell suspensions and a variety of biological tissues. The objective of this study was the investigation of the dielectric properties of living aquatic worms (Lumbriculus variegatus) using impedance spectroscopy in a frequency range between 100 Hz and 10 MHz. We demonstrate a linear relation between the worm biomass and the phase response of the signal thereby providing a quick and precise method to determine the biomass of aquatic worms in situ. Possible applications for nondestructive online biomass monitoring of aquatic worms and other aqueous organisms are discussed. Furthermore, we show that groups of worms fed different diets can be distinguished by the method presented. These results reveal a close relationship between the nutritional composition of the worms and the measured phase response. We also demonstrate that the phase response at 90 kHz does not depend on the worm size. In contrast, the response function for the signal at 440 Hz reveals a linear correlation of average individual worm size and phase. Therefore, we conclude that the measured phase response at 90 kHz qualifies as a measure of the total amount of worm biomass present in the measuring cell, whereas the phase measurement at 440 Hz can be used to estimate the average individual worm size.

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On-Line, Real-Time Measurements of Cellular Biomass using Dielectric Spectroscopy

Cited by 96 publications

References 93 publications

Concepts for the Production of Viruses and Viral Vectors in Cell Cultures

Concepts for the Production of Viruses and Viral Vectors in Cell Cultures

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Biomass measurement of living Lumbriculus variegatus with impedance spectroscopy

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