Difference between revisions of "Zero calibration"

Revision as of 09:32, 5 December 2023

high-resolution terminology - matching measurements at high-resolution

Zero calibration

Description

Zero calibration is, together with air calibration, one of the two steps of the POS calibration. It is performed in the closed chamber after all the oxygen has been depleted by the addition of dithionite or by respiration of imt or cells. Any incubation medium can be used for zero calibration with dithionite or sample. Unlike air calibration, it is not necessary to perform a zero calibration on each experimental day. After performing a zero calibration, it is recommended not running other experiments on the same day. Even after standard cleaning of the O2k-chambers, there might be residual amounts of reduced dithionite in the chamber, affecting the oxygen flux in subsequent experiments performed on the same day.

Abbreviation: R0

Reference: MiPNet06.03 POS-calibration-SOP, O2 calibration - DatLab

MitoPedia O2k and high-resolution respirometry: O2k-Open Support

When

A zero calibration should be performed

From time to time as a record of instrumental performance: use the DatLab-Analysis template.

A zero calibration has to be performed

When measurements are performed at low oxygen (<10 µM).
Bracketing zero calibrations are required when measurements are performed near the limit of detection at oxygen concentrations close to 5 nM (0.005 µM).
When a new or serviced POS is used for the first time.
When a new membrane was applied to the sensor.
When the gain is changed.
When a new OroboPOS-Connector is used.

Incubation medium for zero O2 calibration with dithionite

Any incubation medium can be used for zero calibration with dithionite. MiR05 or a highly concentrated phosphate buffer are needed when using dithionite for measuring of instrumental background oxygen flux, to avoid secondary oxygen-consuming reactions after a step titration of dithionite. For zero calibration, however, an excess dithionite concentration is applied which consumes all dissolved oxygen in the medium, and secondary reactions are not an issue.

Zero current

Each polarographic oxygen sensor has a zero current, i.e., a current [µA] that flows even at an oxygen concentration of zero (which is converted into a voltage [V] as the raw signal by the software DatLab up to version 7). This zero oxygen signal is taken into account by the zero calibration and can be expressed as % of the raw signal at air saturation. New POS have a zero signal below 2 % of the signal at air saturation. For accurate calibration, the zero signal must be stable, which may be the case for zero currents up to 5 % of the signal at air saturation. The stability of the zero current can be assessed by keeping track of calibration values using the "O2k-Calibration-list.xls" template.

A high zero current might not only be caused by the POS, but can also be caused by the O2k-Main Unit, the OroboPOS-Connector, or by dirty electrical connections between those parts.

» Cleaning the electrical connections of the OroboPOS-Connector frequently solves the problem.

» Further details: High signal at zero oxygen

O2k-Manual

» MiPNet06.03 POS-calibration-SOP

Keywords: Oxygen signal

Bioblast links: Oxygen signal - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>

Specific

O2k-Procedures

» High signal at zero oxygen

» POS calibration - static

» POS calibration - dynamic

MiPNet O2k-Procedures

» POS-calibration

» O2k-Manual: POS-service

» O2k-cleaning

» O2k-Series G and DatLab 6: Calibration

General

» Oxygen, dioxygen, O₂

» Oxygen calibration - DatLab

» Oxygen solubility

» Oxygen solubility factor

» Oxygen pressure

» Concentration

» Activity

» Pressure - Pascal

» Barometric pressure

» High-resolution respirometry

» OroboPOS

» Polarographic oxygen sensor

» MitoFit Quality Control System

» Sensitivity

Other keyword lists

» Keywords: Concentration and pressure

MitoPedia methods: Respirometry

MitoPedia O2k and high-resolution respirometry: DatLab

@@ Line 1: / Line 1: @@
 {{MitoPedia
 |abbr=R0
-|description='Zero calibration is together with [[air calibration]] one of the two  steps of the [[POS calibration | OroboPOS calibration]].  It is performed in the  [[closed chamber]] after all the oxygen has been removed  by the addition of [[dithionite]], see [[MiPNet06.03 POS-Calibration-SOP]]. Unlike air  calibration it is not necessary to perform a zero calibration each day.
+|description='''Zero calibration''' is, together with [[air calibration]], one of the two  steps of the POS calibration. It is performed in the [[closed chamber]] after all the oxygen has been depleted by the addition of [[dithionite]] or by respiration of [[Isolated mitochondria |imt]] or [[Living cells |cells]]. Any incubation medium can be used for zero calibration with dithionite or sample. Unlike air calibration, it is not necessary to perform a zero calibration on each experimental day. After performing a zero calibration, it is recommended not running other experiments on the same day. Even after standard cleaning of the O2k-chambers, there might be residual amounts of reduced dithionite in the chamber, affecting the oxygen flux in subsequent experiments performed on the same day.
-|info=[[MiPNet19.18D_O2k-Calibration]]
+|info=[[MiPNet06.03 POS-calibration-SOP]], [[O2 calibration - DatLab]]
 }}
-{{MitoPedia concepts}}
-{{MitoPedia methods
-|mitopedia method=Respirometry, DatLab
-}}
-{{MitoPedia SUIT}}
-{{MitoPedia topics}}
 __TOC__
+{{Template:Technical support integrated}}
+== When ==
+::: '''A zero calibration should be performed'''
+::::* From time to time as a record of instrumental performance: use the [[DatLab-Analysis templates|DatLab-Analysis template]].
-== Zero oxygen calibration in the O2k ==
+::: '''A zero calibration has to be performed'''
-'''A zero calibration should be performed'''
-* From time to time as a record of instrumental performance: use the template [http://www.oroboros.at/?o2k-o2calibration O2k-Calibration-list].
-'''A zero calibration has to be performed'''
+::::* When measurements are performed at low oxygen (<10 µM).
+::::* Bracketing zero calibrations are required when measurements are performed near the limit of detection at oxygen concentrations close to 5 nM (0.005 µM).
+::::* When a new or serviced [[POS]] is used for the first time.
+::::* When a new membrane was applied to the sensor.
+::::* When the [[gain]] is changed.
+::::* When a new [[OroboPOS-Connector]] is used.
-* When measurements are performed at low oxygen (<10 µM).
+== Incubation medium for zero O2 calibration with dithionite ==
-* Bracketing zero calibrations are required when measurements are performed near the limit of detection at oxygen concentrations close to 5 nM (0.005 µM).
-* When a new or serviced [[OroboPOS]] is used for the first time.
+::::  Any incubation medium can be used for zero calibration with dithionite. [[MiR05]] or a highly concentrated phosphate buffer are needed when using dithionite for measuring of [[instrumental background oxygen flux]], to avoid secondary oxygen-consuming reactions after a step titration of dithionite. For zero calibration, however, an excess dithionite concentration is applied which consumes all dissolved oxygen in the medium, and secondary reactions are not an issue.
-* When a new membrane was applied to the sensor.
-* When the [[gain (O2 channel)|gain]] is changed.
-* When a new [[POS connector]] is used.
 == Zero current ==
-Each [[polarographic oxygen sensor]] has a zero current, i.e. a current [µAmp] that flows even at an oxygen concentration of zero, which is converted into a voltage [V] as the raw signal. This zero oxygen signal is taken into account by the zero calibration and can be expressed as % of the [[raw signal at air saturation]]. New OroboPOS have a zero signal below 1% of the signal at air saturation. For accurate calibration, the zero signal must be stable, which may be the case for zeor currents up to c. 5% of the signal at air saturation. The stability of the zero current can be assessed by keeping track of calibration values using the  "O2k-Calibration-list.xls" template.
+:::: Each [[polarographic oxygen sensor]] has a zero current, ''i.e.'', a current [µA] that flows even at an oxygen concentration of zero (which is converted into a voltage [V] as the raw signal by the software DatLab up to version 7). This zero oxygen signal is taken into account by the zero calibration and can be expressed as % of the raw signal at air saturation. New POS have a zero signal below 2 % of the signal at air saturation. For accurate calibration, the zero signal must be stable, which may be the case for zero currents up to 5 % of the signal at air saturation. The stability of the zero current can be assessed by keeping track of calibration values using the  "O2k-Calibration-list.xls" template.
-:» [[MiPNet19.18D O2k-Calibration]].
-A high or unstable zero current is usually caused either by the [[OroboPOS]], by the [[POS connector]] or by a bad connection between those two parts. Cleaning and applying [[contact oil]] to the gold pin and thread connecting the POS-Head and the POS-Connector frequently solves the problem. Otherwise, the problem has to be localized by [[switching components]].
+:::: A high zero current might not only be caused by the [[POS]], but can also be caused by the [[O2k-Main Unit]], the [[OroboPOS-Connector]], or by dirty electrical connections between those parts.
-If the problem is located on the POS head an intensive [[sensor service]], should be applied at least two times. If this does not help the sensor probable has to be replaced.
+::::::» [[OroboPOS-Connector_MitoPedia#Cleaning_the_electrical_connections |Cleaning the electrical connections]] of the OroboPOS-Connector frequently solves the problem.
+::::::» ''Further details:'' [[High signal at zero oxygen]]
-If the problem is located at the POS connector cleaning the connection as described above should be tried again. If the problem was decreased but not solved by cleaning and applying contact oil, the cleaning process may have to be repeated several times. If cleaning the connector does not help the POS connector may have to be replaced.
+== O2k-Manual ==
+::::» [[MiPNet06.03 POS-calibration-SOP]]
-[[Category:Technical service]]
+== Keywords: Oxygen signal ==
+{{Template:Keywords: Oxygen signal}}
+{{MitoPedia methods
+|mitopedia method=Respirometry
+}}
+{{MitoPedia O2k and high-resolution respirometry
+|mitopedia O2k and high-resolution respirometry=DatLab
+}}