On‐line monitoring of hybridoma cell growth using a laser turbidity sensor

Konstantinov, Konstantin; Pambayun, R.; Matanguihan, Ricaredo; Yoshida, Takemi; Perusicn, Cheryl M.; Hu, Wei‐Shou

doi:10.1002/bit.260401107

Cited by 67 publications

(27 citation statements)

References 21 publications

(2 reference statements)

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“…The OUR mainly indicates changes in the metabolism of cultures (Kussow et al 1995;Zeiser et al 2000). In contrast, turbidity and infrared sensors appear to measure the viable cell count during growth phases but also dead cells and debris in later phases of cultivations (Merten et al 1987;Konstantinov et al 1992;Ansorge et al 2007a). The majority of methods for biovolume measurements give identical patterns in situations where viability is high (growth phase) (Ansorge et al 2007b).…”

Section: Resultsmentioning

confidence: 99%

On-line monitoring of responses to nutrient feed additions by multi-frequency permittivity measurements in fed-batch cultivations of CHO cells

2010

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Changes in the nutrient availability of mammalian cell cultures are reflected in the bdispersion parameter characteristic frequency (f C ) and the on-line dual frequency permittivity signal. Multifrequency permittivity measurements were therefore evaluated in fed-batch cultivations of two different CHO cell lines. Similar responses to nutrient depletions and discontinuous feed additions were monitored in different cultivation phases and experimental setups. Sudden increases in permittivity and f C occurred when feed additions were conducted. A constant or declining permittivity value in combination with a decrease in f C indicated nutrient limitations. f C correlated well with changes in oxygen uptake rate when cell diameter remained constant, indicating that metabolic activity is reflected in the value of f C . When significant cell size changes occurred during the cultivations, the analysis of the b-dispersion parameters was rendered complex. For the application of our findings in other systems it will be hence required to conduct additional off-line measurements. Based on these results, it is hypothesized that multi-frequency permittivity measurements can give information on the intracellular or physiological state in fed-batch mode. Similar observations were made when using different cell lines and feeding strategies, indicating that the findings are transferable to other cell lines and systems. The results should lead to an improved understanding of routine fed-batch processes. Additional studies are, however, required to explore how these observations can be used for fed-batch process development and optimization.

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Section: Resultsmentioning

confidence: 99%

On-line monitoring of responses to nutrient feed additions by multi-frequency permittivity measurements in fed-batch cultivations of CHO cells

2010

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“…90 Such measurements are generally linear with cell concentration only at high viabilities, and deviate significantly from linearity with decreasing culture viability, which commonly occur in the latter stages of fed-batch cultures. To overcome such limitations, dielectric permittivity and electrical impedance spectroscopy can be used to monitor viable cell volume.…”

Section: Process Characterization and Validationmentioning

confidence: 99%

Cell Culture Processes in Monoclonal Antibody Production

Li¹,

Shen²,

Amanullah³

2013

Pharmaceutical Sciences Encyclopedia

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This chapter outlines cell culture processes in monoclonal antibody production. Cell culture process development starts with cell line generation and selection, followed by media and culture condition optimization in small‐scale systems, including 96‐well plate, shaker flasks, and bench‐scale bioreactors, for high throughput screening purposes. Once the process conditions are defined, the process is often transferred to the pilot scale to get scale‐up information and to produce toxicology materials and later to cGMP manufacturing for production of clinical material. As development of a commercial cell culture process for production of a biological product is completed at the laboratory and pilot scales, the commercialization process begins with process characterization, scale‐up, technology transfer, and validation for the manufacturing process. The strong demand of therapeutic antibody production, relatively modest titers, and reduction of cost of goods has resulted in a trend toward large‐scale manufacturing. Today, the largest biotech companies are using several hundred to 2,000 L scale bioreactors for early clinical production and 10,000‐25,000 L stirred tank bioreactors to produce commercial products.

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“…8,9 On the other hand, common direct biomass measurement methods like turbidity or in situ microscopy rather follow the total cell concentration and are insensitive to changes in the physiological state of the culture. [10][11][12] Permittivity-based biomass probes are a valuable alternative and their application in cell culture processes is rather novel. They allow in situ application and perform on-line measurements with a quasi-continuous signal (i.e., a very short sample interval of a few seconds to minutes).…”

Section: Introductionmentioning

confidence: 99%

Multifrequency permittivity measurements enable on‐line monitoring of changes in intracellular conductivity due to nutrient limitations during batch cultivations of CHO cells

Ansorge

Esteban

Schmid

2009

Biotechnology Progress

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Lab and pilot scale batch cultivations of a CHO K1/dhfr À host cell line were conducted to evaluate on-line multifrequency permittivity measurements as a process monitoring tool. The b-dispersion parameters such as the characteristic frequency (f C ) and the permittivity increment (De max ) were calculated on-line from the permittivity spectra. The dual-frequency permittivity signal correlated well with the off-line measured biovolume and the viable cell density. A significant drop in permittivity was monitored at the transition from exponential growth to a phase with reduced growth rate. Although not reflected in off-line biovolume measurements, this decrease coincided with a drop in OUR and was probably caused by the depletion of glutamine and a metabolic shift occurring at the same time. Sudden changes in cell density, cell size, viability, capacitance per membrane area (C M ), and effects caused by medium conductivity (r m ) could be excluded as reasons for the decrease in permittivity. After analysis of the process data, a drop in f C as a result of a fall in intracellular conductivity (r i ) was identified as responsible for the observed changes in the dual-frequency permittivity signal. It is hypothesized that the b-dispersion parameter f C is indicative of changes in nutrient availability that have an impact on intracellular conductivity r i . On-line permittivity measurements consequently not only reflect the biovolume but also the physiological state of mammalian cell cultures. These findings should pave the way for a better understanding of the intracellular state of cells and render permittivity measurements an important tool in process development and control.

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On‐line monitoring of hybridoma cell growth using a laser turbidity sensor

Cited by 67 publications

References 21 publications

On-line monitoring of responses to nutrient feed additions by multi-frequency permittivity measurements in fed-batch cultivations of CHO cells

On-line monitoring of responses to nutrient feed additions by multi-frequency permittivity measurements in fed-batch cultivations of CHO cells

Cell Culture Processes in Monoclonal Antibody Production

Multifrequency permittivity measurements enable on‐line monitoring of changes in intracellular conductivity due to nutrient limitations during batch cultivations of CHO cells

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