In-Situ Microscopy Based Monitoring of Mammalian Cell Culture Processes

Joeris, Klaus; Frerichs, Jan-Gerd; Scheper, Thomas; Konstantinov, Konstantin

doi:10.1007/1-4020-3103-3_121

Cited by 21 publications

(24 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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

View full text Add to dashboard Cite

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.

show abstract

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

View full text Add to dashboard Cite

show abstract

“…Specifically, real-time monitoring is advantageous for assessing growth rate, the state of bioreactions, and to obtain early indications of catastrophic events such as contamination or cessation of growth. Many procedures have been previously suggested such as laser turbidity (Konstantinov et al 1992), oxygen uptake rate (OUR), dielectric spectroscopy (Ducommun et al 2001), NIR spectroscopy (Arnold et al 2003), flow injection flow cytometry (Zhao et al 1999), and optical microscopic imaging (Joeris et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Monitoring pH and dissolved oxygen in mammalian cell culture using optical sensors

2008

View full text Add to dashboard Cite

Here, we have studied two parameters critical to process control in mammalian cell culture; dissolved oxygen (dO 2 ) and pH, measured with fluorescent sensors thus allowing the study of the metabolic state of cells in culture without removing or damaging cells during cultivation. Two cell lines, namely, NS0 and CHO were batch-grown in 24-well plates at different serum concentrations with the sensors implemented in the bottom of each well. The data showed a good relationship between the dO 2 and pH data obtained from fluorescent probes and the growth and death characteristics of cells. The method has provided a high throughput on-line multi-parametric analysis of mammalian cell cellular activity.

show abstract

“…Falkner and Gilles 1998;Joeris et al 2002), or indirect follow up via metabolic analysis, have been developed and evaluated, the radio-frequency impedance measurements system seems to be the most interesting. This superiority is because in the latter case, only the living cell number is measured, whereas for the other methods either the total cell number (Merten et al 1987) or the living cell number via sophisticated image analysis (Falkner and Gilles 1998;Joeris et al 2002) or an estimation of the metabolically active biomass are provided. The radio-frequency impedance measurement technique and its industrial applications are reviewed by Carvell and Dowd (in this issue).…”

mentioning

confidence: 99%

Introduction to animal cell culture technology—past, present and future

Merten

2006

Cytotechnology

View full text Add to dashboard Cite

In-Situ Microscopy Based Monitoring of Mammalian Cell Culture Processes

Cited by 21 publications

References 1 publication

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

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

Monitoring pH and dissolved oxygen in mammalian cell culture using optical sensors

Introduction to animal cell culture technology—past, present and future

Contact Info

Product

Resources

About