|
|
| (107 intermediate revisions by 16 users not shown) |
| Line 1: |
Line 1: |
| {{OROBOROS navigation line page name}} | | {{Template:OROBOROS support page name}} |
| {{Publication | | {{Publication |
| |title=[[Image:O2k-Protocols.jpg|right|80px|link=O2k-Protocols|O2k-Protocols]] Polarographic oxygen sensors: calibration, accuracy and quality control SOP. [[Media:MiPNet06.03 POS-Calibration-SOP.pdf |»Bioblast pdf«]] | | |title=[[Image:O2k-Manual.jpg|right|70px|link=O2k-Manual|O2k-Manual]]O2k Quality Control 1: Polarographic oxygen sensors and accuracy of calibration. |
| |info=[http://www.bioblast.at/index.php/File:MiPNet06.03_POS-Calibration-SOP.pdf Versions]
| | |info=[[File:PDF.jpg|100px|link=https://wiki.oroboros.at/images/7/77/MiPNet06.03_POS-Calibration-SOP.pdf |Bioblast pdf]] » [http://www.bioblast.at/index.php/File:MiPNet06.03_POS-Calibration-SOP.pdf Versions] |
| |authors=OROBOROS | | |authors=Oroboros |
| |year=2015-05-10 | | |year=2023-02-06 |
| |journal=Mitochondr Physiol Network | | |journal=Mitochondr Physiol Network |
| |abstract=Gnaiger E (2015) Polarographic oxygen sensors: calibration, accuracy and quality control SOP. Mitochondr Physiol Network 06.03(13):1-8. | | |abstract=Gnaiger E (2023) O2k Quality Control 1: Polarographic oxygen sensors and accuracy of calibration. Mitochondr Physiol Network 06.03(21):1-10. |
| | | {{MiPNet pdf page linking to MitoPedia}} |
| [[High-resolution respirometry]] critically depends on accurate calibration of the [[polarographic oxygen sensor]]s which respond to [[Oxygen_pressure| partial oxygen pressure]]. Expressing the oxygen signal in terms of partial pressure has several advantages, but respiration is expressed in molar units related to biochemical stoichiometries. Conversion of oxygen partial pressure to [[oxygen concentration]] requires accurate information on oxygen solubilities in experimental incubation media. Absolute errors up to 10% are commonly found in the established literature. The [[oxygen solubility]] of mitochondrial respiration medium [[MiR06]] relative to pure water (oxygen solubility factor, ''F''<sub>M</sub>) is 0.92, accurately determined (for MiR05, i.e. MiR06 without catalase; [[MiPNet14.13]]) at 37 °C and 30 °C. At air saturation at standard barometric pressure (100 kPa) and 37 °C, the partial oxygen pressure is 19.63 kPa, and the oxygen concentration is 190.7 µM in MiR06. A clean and ready-to-use O2k-Chamber is a requirement for saving time and quickly calibrating the polarographic oxygen sensors.
| | |mipnetlab=AT_Innsbruck_Oroboros |
| :» Product: [[OroboPOS]], [[Oxygraph-2k]], [[O2k-Catalogue_OROBOROS |O2k-Catalogue]]
| |
| |mipnetlab=AT_Innsbruck_OROBOROS
| |
| }} | |
| {{Labeling
| |
| |area=Instruments;methods | |
| |instruments=Oxygraph-2k, Protocol
| |
| |additional=O2k-SOP
| |
| }} | | }} |
| == Further details ==
| |
| * O2k-Manual: »[[MiPNet19.18D_O2k-Calibration]]«
| |
| * Next step of instrumental quality control: »[[MiPNet14.06 InstrumentalBackground]]«
| |
| * Forstner H, Gnaiger E (1983) Calculation of equilibrium oxygen concentration. In: Polarographic Oxygen Sensors. Aquatic and Physiological Applications. Gnaiger E, Forstner H (eds), Springer, Berlin, Heidelberg, New York:321-33. [[Forstner_1983_POS |»Bioblast Access«]]
| |
|
| |
|
| | == Keywords == |
| | {{Template:Keywords: Oxygen signal}} |
|
| |
|
| [[Image:MiPNet06.03_Table.jpg|centre|frame|<sup>c</sup>O2* is the oxygen concentration at thermodynamic equilibrium with air under standard conditions of 100 kPa barometric pressure. FM has been determined for MiR05 at 30 °C and 37 °C, and is assumed to be identical at 25 °C.]] | | ::::» [[Oxygen calibration - DatLab]] |
|
| |
|
| == O2 sensor test ==
| |
| {{Technical support integrated}}
| |
| {{#set:Technical service=O2 sensor|Technical service=POS connector|Technical service=O2 signal|Technical service=Main unit|Technical service=Performance test}}
| |
| '''The O<sub>2</sub> sensor test is described as an [[OroboPOS]]''' standard operating procedure: »Bioblast pdf (on top of page).
| |
|
| |
|
| '''When should an O2-sensor test be performed?'''
| | {{Labeling |
| * After switching on the O2k, every day: air calibration and stirrer test.
| | |area=Respiration, Instruments;methods |
| * Zero oxygen calibration: from time to time over weeks; bracketing zero oxygen calibrations when working at low oxygen.
| | |instruments=Oxygraph-2k, O2k-Manual |
| * After application of a new membrane and O2-sensor service: In some cases, the signal of the OroboPOS improves (higher signal stability, less noise, shorter response time), when the O2k remains switched on over night (O2k-Chambers filled with 70% EtOH).
| | |additional=DatLab, O2k-SOP, DL7, Oxygen solubility, DL8, |
| * During troubleshooting, particularly when [[switching components]] between the two chambers, a quick sensor test is performed after each step (stirrer test, sensor signal).
| | MitoFit 2021 Dark respiration, MitoFit 2021 Photosynthesis, DL8, PLoSONE2022ace-sce, MitoFit2022QC, POS |
| '''Main criteria for sensor performance'''
| | }} |
| * [[Raw signal at air saturation]]
| |
| * [[Zero current |Raw signal at zero oxygen]]
| |
| * [[Signal stability]]: drift and noise
| |
| | |
| | |
| == Response time of the POS ==
| |
| {{Technical support integrated}} | |
| {{#set:Technical service=O2 sensor|Technical service=O2 signal}}
| |
| The response time of the [[Polarographic oxygen sensor]] is assessed in the [[Stirrer test]] that is part of a full [[Sensor test]]. A quantitative interpretation of the stirrer test will yield the time constant of the sensor. Such a quantitative calculation is indeed necessary for kinetic work. However, to access the suitability of a sensor for standard steady state work each user will soon gain the necessary experience to judge the outcome of a stirrer test.
| |
| :>> Example: Download [http://www.oroboros.at/index.php?id=sensor_test here].
| |
| | |
| For how to improve the response time of a POS, see
| |
| [[Slow responding sensor]].
| |
| | |
| The response time of the sensor is just one of several factors determining the [[time resolution]].
| |
| | |
|
| |
| == Stirrer test ==
| |
| {{Technical support integrated}}
| |
| {{#set:Technical service=O2 sensor|Technical service=O2 signal|Technical service=Performance test}}
| |
| The [[response time of the POS]] can be most conveniently checked by a stirrer test, see
| |
| [[MiPNet06.03_POS-Calibration-SOP]], section 3.
| |
| The stirrer test is part of the [[Sensor test]] and of our proposed quality checks before every experiment described in the link above. see If the results of a stirrer test are not satisfactory the procedures suggested for a [[Slow responding sensor]] should be followed. DatLab supports an automatically controlled stirrer test [F9].
| |
| | |
| | |
| Background information
| |
| After switching off the stirrer the electrolyte reservoir will quickly be depleted of oxygen by the oxygen consumption of the sensor. Oxygen can only reach the sensor now in a unstirred diffusion process, therefore a new and lower equilibrium O2 concentration is established in the vicinity of the sensor. After switching the stirrer on again the O2 concentration near the sensor is quickly brought back to the same level as elsewhere in the chamber, however the sensor takes some time to respond to this change. Thus the response time of the sensor can be determined. A stirrer tests does not influence the O2 concentration in the entire chamber. A stirrer test can not be at a chamber oxygen concentration of zero (or near zero) because no change in the O2 signal will result.
| |
|
| |
| == This article is cited in ==
| |
| | |
| * Rodriguez JV, Pizarro MD, Scandizzi AL, Guibert EE, Almada LL, Mamprin ME (2008) Construction and performance of a minibioreactor suitable as experimental bioartificial liver. Artif Organs 32:323-8. [http://www.ncbi.nlm.nih.gov/pubmed/18370948 »PubMed 18370948«]
| |
| | |
|
| |
| [[Category:Technical service]]
| |
» Versions
