A study of oxygen transfer in shake flasks using a non-invasive oxygen sensor

2003 ◽  
Vol 84 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Atul Gupta ◽  
Govind Rao
Keyword(s):  
Oxygen Transfer ◽  
Oxygen Sensor ◽  
Non Invasive ◽  
Shake Flasks

scholarly journals Time-Resolved Monitoring of the Oxygen Transfer Rate of Chinese Hamster Ovary Cells Provides Insights Into Culture Behavior in Shake Flasks

2021 ◽  
Vol 9 ◽  
Author(s):  
Nina Ihling ◽  
Lara Pauline Munkler ◽  
Christoph Berg ◽  
Britta Reichenbächer ◽  
Johannes Wirth ◽  
...  
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Shake Flask ◽  
Oxygen Transfer Rate ◽  
Carbon Sources ◽  
Chinese Hamster ◽  
Respiration Activity ◽  
Time Resolved ◽  
Non Invasive ◽  
Shake Flasks

Cultivations of mammalian cells are routinely conducted in shake flasks. In contrast to instrumented bioreactors, reliable options for non-invasive, time-resolved monitoring of the culture status in shake flasks are lacking. The Respiration Activity Monitoring Respiration Activity Monitoring System system was used to determine the oxygen transfer rate (OTR) in shake flasks. It was proven that the OTR could be regarded as equal to the oxygen uptake rate as the change of the dissolved oxygen concentration in the liquid phase over time was negligibly small. Thus, monitoring the oxygen transfer rate (OTR) was used to increase the information content from shake flask experiments. The OTR of a Chinese hamster ovary cell line was monitored by applying electrochemical sensors. Glass flasks stoppered with cotton plugs and polycarbonate flasks stoppered with vent-caps were compared in terms of mass transfer characteristics and culture behavior. Similar mass transfer resistances were determined for both sterile closures. The OTR was found to be well reproducible within one experiment (standard deviation <10%). It correlated with changes in cell viability and depletion of carbon sources, thus, giving more profound insights into the cultivation process. Culture behavior in glass and polycarbonate flasks was identical. Monitoring of the OTR was applied to a second culture medium. Media differed in the maximum OTR reached during cultivation and in the time when all carbon sources were depleted. By applying non-invasive, parallelized, time-resolved monitoring of the OTR, the information content and amount of data from shake flask experiments was significantly increased compared to manual sampling and offline analysis. The potential of the technology for early-stage process development was demonstrated.

Scale-up from shake flasks to fermenters in batch and continuous mode withCorynebacterium glutamicum on lactic acid based on oxygen transfer and pH

2007 ◽  
Vol 98 (4) ◽  
pp. 800-811 ◽  
Author(s):  
Juri M. Seletzky ◽  
Ute Noak ◽  
Jens Fricke ◽  
Eike Welk ◽  
Werner Eberhard ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Oxygen Transfer ◽  
Scale Up ◽  
Continuous Mode ◽  
Shake Flasks

scholarly journals Oxygenation failure after cardiac surgery: early re-intubation versus treatment by nasal continuous positive airway pressure (NCPAP) or non-invasive positive pressure ventilation (NPPV)

2016 ◽  
Vol 70 (2) ◽  
Author(s):  
Muhammed Kurt ◽  
Udo Boeken ◽  
Jens Litmathe ◽  
Peter Feindt ◽  
Emmeran Gams
Keyword(s):  
Cardiac Surgery ◽  
Respiratory Failure ◽  
Oxygen Transfer ◽  
Airway Pressure ◽  
Positive Pressure Ventilation ◽  
Positive Airway Pressure ◽  
Positive Pressure ◽  
Non Invasive ◽  
Group A ◽  
Group B

Background: Due to an increasing incidence of respiratory failure after cardiac surgery we wanted to study whether nasal continuous positive airway pressure (NCPAP) may improve pulmonary oxygen transfer and may avoid reintubation after coronary operations. Additionally, we compared this protocol to non-invasive positive pressure ventilation (NPPV). Methods: For a period of 2 years we analyzed all patients that were extubated within 12 hours after coronary surgery, and in whom oxygen transfer (PaO2/FIO2) deteriorated without hypercapnia so that all these patients met predefined criteria for reintubation: group A=immediate reintubation (n=88), group B=NCPAP-treatment (n=173), group C=NPPV(n=18). Results: 25,4% of group B- and 22,2% of group C-patients were also intubated after a period of NCPAP or NPPV. All other patients of groups B and C could be weaned from these devices (B = 34.3 ± 5.9 hours; C = 26.4 ± 4.4 h; p<0.05) and were well oxygenated by face mask at ambient pressure (Ratio PaO2/FIO2: B, 138 ± 13; C, 140 ± 13). In group A we found a higher mortality (7.95%) compared to group B (4.04%) and group C (5.55%). NCPAP-patients suffered more frequently from an impaired sternal wound healing (A = 4.5%, B = 8.6%; p<0.05). Conclusions: We conclude that reintubation after cardiac operations should be avoided since NCPAP and NPPV are safe and effective to improve arterial oxygenation in most patients with non hypercapnic respiratory failure.

scholarly journals The metabolic switch can be activated in a recombinant strain of Streptomyces lividans by a low oxygen transfer rate in shake flasks

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Ramsés A. Gamboa-Suasnavart ◽  
Norma A. Valdez-Cruz ◽  
Gerardo Gaytan-Ortega ◽  
Greta I. Reynoso-Cereceda ◽  
Daniel Cabrera-Santos ◽  
...  
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Recombinant Strain ◽  
Oxygen Transfer Rate ◽  
Streptomyces Lividans ◽  
Low Oxygen ◽  
Metabolic Switch ◽  
Shake Flasks

scholarly journals Using Colour Images for Online Yeast Growth Estimation

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 894
Author(s):  
Elias August ◽  
Besmira Sabani ◽  
Nurdzane Memeti
Keyword(s):  
Measurement Techniques ◽  
Region Of Interest ◽  
Non Invasive ◽  
Model Predictions ◽  
Density Values ◽  
Colour Changes ◽  
Shake Flasks ◽  
Research Questions ◽  
Growth Estimation ◽  
Invasive Measurement

Automatisation and digitalisation of laboratory processes require adequate online measurement techniques. In this paper, we present affordable and simple means for non-invasive measurement of biomass concentrations during cultivation in shake flasks. Specifically, we investigate the following research questions. Can images of shake flasks and their content acquired with smartphone cameras be used to estimate biomass concentrations? Can machine vision be used to robustly determine the region of interest in the images such that the process can be automated? To answer these questions, 18 experiments were performed and more than 340 measurements taken. The relevant region in the images was selected automatically using K-means clustering. Statistical analysis shows high fidelity of the resulting model predictions of optical density values that were based on the information embedded in colour changes of the automatically selected region in the images.

Closure effects on oxygen transfer and aerobic growth in shake flasks

2006 ◽  
Vol 95 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Hossein Nikakhtari ◽  
Gordon A. Hill
Keyword(s):  
Oxygen Transfer ◽  
Aerobic Growth ◽  
Shake Flasks
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