Difference between revisions of "Talk:Respiratory acceptor control ratio"
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[[Respiratory control ratio]] has been accessed more than | [[Image:BB-Bioblast.jpg|left|30px|link=http://www.bioblast.at/index.php/Bioblast:About|Bioblast wiki]] | ||
* 5,000 times (2013-05-17) | == Popular Bioblast page == | ||
::: [[Respiratory acceptor control ratio]] has been accessed more than | |||
::::* 15,000 times (2019-03-13) | |||
::::* 10,000 times (2015-11-12) | |||
::::* 5,000 times (2013-05-17) | |||
== Problem: The RCR is low in isolated mitochondria == | |||
At a high mitochondrial concentration (0.5 mg protein/ml), ADP is exhausted very rapidly if added at a concentration typically used for [[State 3]] measurements (200-300 µM), which may stimulate flux below the ADP-saturated state of [[OXPHOS capacity]]. The slope increases sharply and returns to [[State 4]] ([[LEAK respiration]]), even before the plot of flux shows the true maximum, resulting in a low apparent RCR. | |||
<big>'''Tests and solutions'''</big> | |||
# Reduce the data recording interval (standard is 2 seconds) to the minimum of 0.2 s (setting in the O2k control window; see [[MiPNet22.11 O2k-FluoRespirometer manual]]). As the data recording interval is reduced, the flux appears more noisy, but represents transitions more accurately and reduces the apparent time-delay. At high flux per volume, the increased noise level presents no problem. Flux then shows a period of constant OXPHOS capacity rather than a sharp peak. | |||
# Reduce the mitochondrial concentration, thus prolonging the duration of ADP-saturated respiration (OXPHOS capacity) over 120 seconds. If flux reaches a constant maximum value, then analysis is possible without application of signal deconvolution (standard plot of flux in DatLab). | |||
# Otherwise, export the data into [http://www.oroboros.at/?O2k-datlab2 DatLab 2], and apply a time correction (signal deconvolution), as described by [[Gnaiger 2001 Respir Physiol]]. | |||
# See also ‘Notes on [[Time resolution]]’. | |||
Latest revision as of 12:25, 25 November 2020
Popular Bioblast page
- Respiratory acceptor control ratio has been accessed more than
- 15,000 times (2019-03-13)
- 10,000 times (2015-11-12)
- 5,000 times (2013-05-17)
- Respiratory acceptor control ratio has been accessed more than
Problem: The RCR is low in isolated mitochondria
At a high mitochondrial concentration (0.5 mg protein/ml), ADP is exhausted very rapidly if added at a concentration typically used for State 3 measurements (200-300 µM), which may stimulate flux below the ADP-saturated state of OXPHOS capacity. The slope increases sharply and returns to State 4 (LEAK respiration), even before the plot of flux shows the true maximum, resulting in a low apparent RCR.
Tests and solutions
- Reduce the data recording interval (standard is 2 seconds) to the minimum of 0.2 s (setting in the O2k control window; see MiPNet22.11 O2k-FluoRespirometer manual). As the data recording interval is reduced, the flux appears more noisy, but represents transitions more accurately and reduces the apparent time-delay. At high flux per volume, the increased noise level presents no problem. Flux then shows a period of constant OXPHOS capacity rather than a sharp peak.
- Reduce the mitochondrial concentration, thus prolonging the duration of ADP-saturated respiration (OXPHOS capacity) over 120 seconds. If flux reaches a constant maximum value, then analysis is possible without application of signal deconvolution (standard plot of flux in DatLab).
- Otherwise, export the data into DatLab 2, and apply a time correction (signal deconvolution), as described by Gnaiger 2001 Respir Physiol.
- See also ‘Notes on Time resolution’.
