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Difference between revisions of "Oxygen signal"

From Bioblast
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== O2k-Open Support cases ==
== O2k-Open Support cases ==


:::Anonymous user
{{Template:OSC Oxygen signal1}}
Β 
Question:
Β 
Q1: The Oxygen Concentration couldn't go down while I tried zero oxygen calibration. No matter how much solution I added, the oxygen concentration still remain the same. I reassembled, but it still keeps the same. The data is attached.
Β 
[[File:No_response_to_dithionite.PNG|center|600px]]
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Β 
Q2: The chamber B's oxygen slope is not stable. This is a new problem I have never seen. Please see the attachment.(2019-04-26)
[[File:Signal_stability.PNG|center|600px]]
Β 
Β 
Q3. The maximum Oxygen concentration of another Oroboros machine is only about 140. I don't how to increase the starting point of oxygen concentration.
Β 
Β 
Answer:
Β 
A1: I suspect that the dithionite solution was not correctly prepared or not fresh. Dithionite loses activity quite fast, so you need to make it freshly. Please check this site: http://bioblast.at/index.php/Dithionite
Β 
A2: While there is a difference between chambers A and B, the stability of the signal is still within the acceptable range of noise given by the specifications of the instrument, see: [[Oxygen_sensor_test | Oxygen_sensor_test]].
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A3: You may simply need to calibrate, please see here: http://wiki.oroboros.at/index.php/O2_calibration_-_DatLab

Revision as of 16:23, 16 July 2019


high-resolution terminology - matching measurements at high-resolution


Oxygen signal

Description

The oxygen signal of the OROBOROS O2k is transmitted from the electrochemical polarographic oxygen sensor (OroboPOS) for each of the two chambers to DatLab. The primary signal is a current [mAmp] which is converted into a voltage [V], and calibrated in SI units for amount of substrance concentration [Β΅mol.dm-3 or Β΅M].


Reference: MiPNet19.18D O2k-Series G and DatLab 6: Calibration, MiPNet06.03 POS-calibration-SOP

|mitopedia method=Respirometry }}

MitoPedia O2k and high-resolution respirometry: O2k hardware, DatLab 


Template NextGen-O2k.jpg


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



Stability of the oxygen signal

The stability of the oxygen signal of the O2k is evaluated by the (negative) uncorrected slope over time. After smoothing, the slope of a stable sensor should be less than +- 1 pmol.s-1.ml-1 in a 2-ml chamber.

  • Instability of the oxygen signal
  • There is drift of the oxygen signal over short or long periods of time.
  • The signal at air saturation is abnormally high for a given gain setting.
  • The zero current is high (>2.5%) and may show drift.

Oxygen signal does not respond

  • The oxygen signal remains at or close to zero even at high oxygen levels.
  • The signal at air saturation is abnormally low.
  1. Check the gain setting for the affected oxygen channel. Set to Gain 1.
  2. Apply technical service: O2k-Open Support

O2k-Open Support cases

Anonymous user

Question:

Q1: The Oxygen Concentration couldn't go down while I tried zero oxygen calibration. No matter how much solution I added, the oxygen concentration still remain the same. I reassembled, but it still keeps the same. The data is attached.

No response to dithionite.PNG


Q2: The chamber B's oxygen slope is not stable. This is a new problem I have never seen. Please see the attachment.(2019-04-26)

Signal stability.PNG


Q3. The maximum Oxygen concentration of another Oroboros O2k is only about 140 ΞΌM. I don't how to increase the starting point of oxygen concentration.


Answer:

A1: I suspect that the dithionite solution was not correctly prepared or not fresh. Dithionite loses activity quite fast, so you need to make it freshly. Please check this site: http://bioblast.at/index.php/Dithionite

A2: While there is a difference between chambers A and B, the stability of the signal is still within the acceptable range of noise given by the specifications of the instrument, see: Oxygen_sensor_test.

A3: You may simply need to calibrate, please see here: http://wiki.oroboros.at/index.php/O2_calibration_-_DatLab