Potential errors in conventional DOT measurement techniques in shake flasks and verification using a rotating flexitube optical sensor
2011

Errors in Measuring Oxygen in Shake Flasks

publication Evidence: high

Author Information

Author(s): Sven Hansen, Frank Kensy, Andreas Käser, Jochen Büchs

Primary Institution: RWTH Aachen University

Hypothesis

Conventional methods for measuring dissolved oxygen tension (DOT) in shake flasks may produce erroneous results.

Conclusion

The Clark-type electrode is unsuitable for measuring DOT, while the new rotating flexitube optical sensor provides more accurate measurements.

Supporting Evidence

  • Clark-type electrodes increase oxygen transfer capacity but alter hydrodynamics.
  • Fixed sensor spots may not always contact the bulk liquid, leading to erroneous DOT readings.
  • The rotating flexitube optical sensor maintains contact with the bulk liquid, providing accurate measurements.

Takeaway

This study shows that using certain sensors to measure oxygen in shake flasks can give wrong results, but a new type of sensor works better.

Methodology

The study compared the performance of Clark-type electrodes and a new rotating flexitube optical sensor in measuring DOT during fermentation processes.

Potential Biases

The fixed sensor spot may register gas in the headspace instead of the actual liquid, leading to inaccurate measurements.

Limitations

The rotating flexitube optical sensor requires a complicated setup and is not as durable as fixed sensor systems.

Digital Object Identifier (DOI)

10.1186/1472-6750-11-49

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