Cookies help us deliver our services. By using our services, you agree to our use of cookies. More information

Difference between revisions of "O2k-Specifications"

From Bioblast
 
(105 intermediate revisions by 13 users not shown)
Line 1: Line 1:
{{Mainpage orobopedia}}
{{Technical support}}
{{Product
__TOC__
|description='''O2k''' stands for Oxygraph-2k and '''high-resolution respirometry''', meeting powerful quality criteria thus securing '''high output'''. 'High throughput' stands for '''multiwell''' systems. In respirometry, this is ''not equivalent to high output''.
{{MitoPedia without banner
|product id=*****<sup>---</sup>
|abbr=
|product type=O2k, Feedback
|description=[[Image:O2k-Info.png|right|30px|link=Oroboros O2k]]'''O2k versus multiwell respirometer''': '''O2k''' stands for Oroboros O2k and '''[[high-resolution respirometry]]''', meeting powerful quality criteria securing '''high output''' and pioneering state-of-the-art [[Gnaiger_2012_MitoPathways|comprehensive OXPHOS analysis]] of substrate control and coupling control of mitochondrial function. 'High throughput' stands for disposable multiwell systems - expensive, with limited scope and extremely high running costs. In respirometry, high throughput is not equivalent to high output. ''If you’re using a biased instrument, it doesn’t matter how many measurements you take – you’re aiming at the wrong target'' ([[Silver 2012 Penguin Press]]).
|product image=[[Image:O2k-Info.png|right|30px|caption]]
|info= [[MiPNet18.10 O2k-Specifications]], [http://wiki.oroboros.at/images/9/93/Flyer_backside_.png Flyer with specification summary]
}}
{{MitoPedia O2k and high-resolution respirometry
|mitopedia O2k and high-resolution respirometry=O2k hardware
}}
}}


__TOC__
[[File:Questions.jpg|left|40px]]
 
<br />
== Comparison of HRR with other respirometric methods ==
<div class="toccolours mw-collapsible mw-collapsed">
 
::: <span style="font-size:105%; color:##424242">'''» Keywords'''</span>
::* [[Horan 2012 J Gerontol A Biol Sci Med Sci|Review: Quantifying mitochondrial dysfunction in complex diseases of aging (Horan et al 2012)]]
<div class="mw-collapsible-content">
::* [http://www.nature.com/nprot/journal/v7/n6/fig_tab/nprot.2012.048_T1.html Comparison of common bioenergetic analysis methods] ([[Zhang 2012 Nat Protoc|Zhang 2012 Nat Protoc]])
::::» [[Gnaiger 2012 MitoPathways|Comprehensive OXPHOS analysis]]
::* Discussion: [[Talk:Rogers 2011 PLoS One|Seahorse XF for isolated mitochondria - High throughput without high output?]] - [[Talk:O2k versus multiwell respirometer|Continue the discussion]]
:::[[High-output, low running costs]]
 
:::[[O2k-Publications: Topics]]
 
:::[[Power-O2k]]
== O2k: High-output replaces wasteful high-throughput ==
::::» [[Specifications of the O2k]]'''
 
</div>
::The OROBOROS [[Oxygraph-2k]] for [[high-resolution respirometry]] (HRR) is the gold standard for highly accurate quantitative measurements, using low amounts of sample.  Instrumental and methodological approaches require an advancing level of [http://www.oroboros.at/?QA-in-Respirometry Quality Assurance] in research and clinical applications.
</div>
 
<br />
::Lack of Quality Assurance yields publications which may pass the scientific reviewing system without meeting basic scientific quality criteria. For a discussion of a publication based on a multiwell system (Rogers et al 2011 PLoS One), see >> [[Rogers 2011 PLoS One|Discussion: HRR versus multiwell]].
 
 
== Is plastic compatible with respirometry? ==


'''A. O2k'''


::The O2k-durane glass chambers are closed by PVDF or PEEK stoppers which are as diffusion tight as titanium stoppers (originally used in O2k-Series A and B). The magnetic stirrer bars are coated by PVDF or PEEK.  Viton O-rings used for sealing of the stoppers, and butyl rubber gaskets provide the seals for the oxygen sensors. 


::The O2k not only minimizes the effect of backdiffusion by avoiding inappropriate plastic materials, but additionally implements automatic correction for instrumental background flux (see [http://www.oroboros.at/?O2k-Specifications O2k-specifications]).  
== Combination of interests ==
:::: [[Gnaiger E|Erich Gnaiger]] is founder and CEO of Oroboros Instruments, and responsible for the development of the O2k in collaboration with the O2k-Team and our partners. A series of methodological publications is the result of positive feedback between his work as faculty staff of the Medical University of Innsbruck, his company initiatives and numerous international cooperations.


::>>> More information @OROBOROS: [http://www.oroboros.at/index.php?backgroundcorrection Plastic materials with high oxygen diffusion are eliminated from the O2k-Chamber]. 


'''B. Multiwell'''
== Selected references ==


::Oxygen storage in the plastic material of multiwell plates leads to high oxygen backdiffusion. Since the problems are well known ([[Gnaiger_1995_JBB]]), specifications should be provided on backdiffusion, and test protocols applied to enable evaluation of such specifications ([[Gnaiger_2008_POS|Gnaiger 2008]]). 
  [[Comparison of respirometric methods]] - [[Talk:Comparison of respirometric methods | Discussion]]


::At the high surface-to-volume ratio in a small well, the problem is not restricted to oxygen diffusion, but all lipid soluble substances partition between the aqueous and plastic phases, such that the surface-attached biological sample is exposed to undefined effective concentrations.  
::::* Horscroft JA, Kotwica AO, Laner V, West JA, Hennis PJ, Levett DZH, Howard DJ, Fernandez BO, Burgess SL, Ament Z, Gilbert-Kawai ET, Vercueil A, Landis BD, Mitchell K, Mythen MG, Branco C, Johnson RS, Feelisch M, Montgomery HE, Griffin JL, Grocott MPW, Gnaiger E, Martin DS, Murray AJ (2017) Metabolic basis to Sherpa altitude adaptation. Proc Natl Acad Sci U S A 114:6382–7. - [[Horscroft 2017 Proc Natl Acad Sci U S A |»Bioblast link«]]


::Microplate readers may have inherent plastic-related problems in the context of enzyme activity assays: [[Talk:MiPNet08.14 CitrateSynthase]].
::::* Lemieux H, Blier PU, Gnaiger E (2017) Remodeling pathway control of mitochondrial respiratory capacity by temperature in mouse heart: electron flow through the Q-junction in permeabilized fibers. Sci Rep 7:2840. - [[Lemieux 2017 Sci Rep |»Bioblast link«]]


::::* Lemieux H, Subarsky P, Doblander C, Wurm M, Troppmair J, Gnaiger E (2017) Impairment of mitochondrial respiratory function as an early biomarker of apoptosis induced by growth factor removal. bioRxiv doi: https://doi.org/10.1101/151480. - [[Lemieux 2017 bioRxiv 151480 |»Bioblast link«]]


== How high are the running costs? ==
::::* Gnaiger E, Boushel R, Søndergaard H, Munch-Andersen T, Damsgaard R, Hagen C, Díez-Sánchez C, Ara I, Wright-Paradis C, Schrauwen P, Hesselink M, Calbet JAL, Christiansen M, Helge JW, Saltin B (2015) Mitochondrial coupling and capacity of oxidative phosphorylation in skeletal muscle of Inuit and caucasians in the arctic winter. Scand J Med Sci Sports 25 (Suppl 4):126–34. - [[Gnaiger 2015 Scand J Med Sci Sports| »Bioblast link«]]


'''A. O2k'''
::::* Harrison DK, Fasching M, Fontana-Ayoub M, Gnaiger E (2015) Cytochrome redox states and respiratory control in mouse and beef heart mitochondria at steady-state levels of hypoxia. J Appl Physiol 119:1210-8. - [[Harrison 2015 J Appl Physiol |»Bioblast link«]]


::The [http://www.oroboros.at/index.php?low-o2k-running-costs running costs for the OROBOROS O2k] are '''very very low'''.
::::* Makrecka-Kuka M, Krumschnabel G, Gnaiger E (2015) High-resolution respirometry for simultaneous measurement of oxygen and hydrogen peroxide fluxes in permeabilized cells, tissue homogenate and isolated mitochondria. Biomolecules 5:1319-38. - [[Makrecka-Kuka 2015 Biomolecules |»Bioblast link«]]


'''B. Multiwell'''
::::* Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. Bioenerg Commun:112 pp. »[[Gnaiger 2020 BEC MitoPathways |Bioblast link«]]


::The '''running costs are extremely high''', based on expensive dischargeable wells for single use only.
::::* Pesta D, Gnaiger E (2012) High-resolution respirometry. OXPHOS protocols for human cells and permeabilized fibres from small biopsies of human muscle. Methods Mol Biol 810:25-58. [[Pesta 2012 Methods Mol Biol |»Bioblast link«]]


::How many of the wells of a dischargeable plate can actually be used for independent measurements?  Several wells are required for calibration, edge effects may eliminate the use of wells on the sides.  
::::* Votion DM, Gnaiger E, Lemieux H, Mouithys-Mickalad A, Serteyn D (2012) Physical fitness and mitochondrial respiratory capacity in horse skeletal muscle. PLoS One 7: e34890. [[Votion 2012 PLoS One ||»Bioblast link«]]


::Elaborating a protocol for starting an experimental series requires a large number of test runs, such that the cost of discharged wells in an entire experiment approaches the investment into a second O2k.  
::::* Lemieux H, Semsroth S, Antretter H, Höfer D, Gnaiger E (2011) Mitochondrial respiratory control and early defects of oxidative phosphorylation in the failing human heart. Int J Biochem Cell Biol 43:1729–38. - [[Lemieux 2011 Int J Biochem Cell Biol |»Bioblast link«]]


::::* Pesta D, Hoppel F, Macek C, Messner H, Faulhaber M, Kobel C, Parson W, Burtscher M, Schocke M, Gnaiger E (2011) Similar qualitative and quantitative changes of mitochondrial respiration following strength and endurance training in normoxia and hypoxia in sedentary humans. Am J Physiol Regul Integr Comp Physiol 301:R1078–87. - [[Pesta 2011 Am J Physiol Regul Integr Comp Physiol |»Bioblast link«]]


== Power-O2k - a 'best' investment ==
::::* Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: facts and artefacts in mitochondrial oxygen kinetics. Adv Exp Med Biol 662:7-25. - [[Scandurra 2010 Adv Exp Med Biol |»Bioblast link«]]


:: The OROBOROS O2k is not suited for a high-throughput approach.  However, investing the identical amount of money, a large number of O2k chambers provides a unique high-throughput HRR system for quantitative O2k-measurements at low running costs.
::::* Aguirre E, Rodríguez-Juárez F, Bellelli A, Gnaiger E, Cadenas S (2010) Kinetic model of the inhibition of respiration by endogenous nitric oxide in intact cells. Biochim Biophys Acta 1797:557-65. - [[Aguirre 2010 Biochim Biophys Acta ||»Bioblast link«]]


::>>> More information @OROBOROS: [http://www.oroboros.at/?Power-O2k Power-O2k]
::::* Aragonés J, Schneider M, Van Geyte K, Fraisl P, Dresselaers T, Mazzone M, Dirkx R, Zacchigna S, Lemieux H, Jeoung NH, Lambrechts D, Bishop T, Lafuste P, Diez-Juan A, K Harten S, Van Noten P, De Bock K, Willam C, Tjwa M, Grosfeld A, Navet R, Moons L, Vandendriessche T, Deroose C, Wijeyekoon B, Nuyts J, Jordan B, Silasi-Mansat R, Lupu F, Dewerchin M, Pugh C, Salmon P, Mortelmans L, Gallez B, Gorus F, Buyse J, Sluse F, Harris RA, Gnaiger E, Hespel P, Van Hecke P, Schuit F, Van Veldhoven P, Ratcliffe P, Baes M, Maxwell P, Carmeliet P (2008) Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism. Nat Genet 40:170-80. - [[Aragones 2008 Nat Genet |»Bioblast link«]]


::::* Gnaiger E (2008) Polarographic oxygen sensors, the oxygraph and high-resolution respirometry to assess mitochondrial function. In: Mitochondrial Dysfunction in Drug-Induced Toxicity (Dykens JA, Will Y, eds) John Wiley:327-52. - [[Gnaiger_2008_POS |»Bioblast link«]]


== Are multiple substrate-uncouplier-inhibitor titrations possible? ==
::::* Hütter E, Renner K, Pfister G, Stöckl P, Jansen-Dürr P, Gnaiger E (2004) Senescence-associated changes in respiration and oxidative phosphorylation in primary human fibroblasts. Biochem J 380:919-28. - [[Huetter_2004_Biochem J |»Bioblast link«]]
'''A. O2k'''


::[[Substrate-uncoupler-inhibitor titration]] (SUIT) protocols have been developed for diagnostic tests of mitochondrial respiratory function, to study the complex interactions of coupling control and substrate control in a single assay, thus increasing the information obtained per unit sample and per unit time. Up to 20 titration steps may be included in a single SUIT protocol.  
::::* Kuznetsov AV, Schneeberger S, Seiler R, Brandacher G, Mark W, Steurer W, Saks V, Usson Y, Margreiter R, Gnaiger E (2004) Mitochondrial defects and heterogeneous cytochrome ''c'' release after cardiac cold ischemia and reperfusion. Am J Physiol Heart Circ Physiol 286:H1633–41. - [[Kuznetsov_2004_Am_J_Physiol_Heart_Circ_Physiol |»Bioblast link«]]


::>>> More information @OROBOROS: [http://www.oroboros.at/?Protocols_Muscle_Horse O2k-Protocol: Substrate-uncoupler-inhibitor titration]
::::* Gnaiger E (2001) Bioenergetics at low oxygen: dependence of respiration and phosphorylation on oxygen and adenosine diphosphate supply. Respir Physiol 128:277-97. - [[Gnaiger 2001 Respir Physiol |»Bioblast link«]]


'''B. Multiwell'''
::::* Gnaiger E, Méndez G, Hand SC (2000) High phosphorylation efficiency and depression of uncoupled respiration in mitochondria under hypoxia. Proc Natl Acad Sci U S A 97:11080-5. [[Gnaiger 2000 Proc Natl Acad Sci U S A |»Open Access«]]


::The number of different substances that can be titrated into a well is limited, such that modern SUIT protocols cannot be applied in multiwell systems.  A 24 well plate with four titrations per well, or a 96 well plate with two titrations per well are insufficient for obtaining the information from a SUIT experiment. The multiwell approach, therefore, yields rather low throughput.
::::* Steinlechner-Maran R, Eberl T, Kunc M, Margreiter R, Gnaiger E (1996) Oxygen dependence of respiration in coupled and uncoupled endothelial cells. Am J Physiol Cell Physiol 271:C2053-61. - [[Steinlechner-Maran_1996_Am J Physiol Cell Physiol |»Bioblast link«]]


::::* Gnaiger E, Steinlechner-Maran R, Méndez G, Eberl T, Margreiter R (1995) Control of mitochondrial and cellular respiration by oxygen. J Bioenerg Biomembr 27:583-96. - [[Gnaiger 1995 J Bioenerg Biomembr |»Bioblast link«]]


== Quantitative respirometry ==


'''A. O2k'''


::HRR is the result of long-term expertise in instrumental design, software development, and experimental protocols developed for mitochondrial physiology, clinical and pharmacological applications. Taken together, these developments resulted in new qualitative and quantitative standards summarized as the [http://www.oroboros.at/index.php?o2k-concept O2k-Concept].


::The [http://www.oroboros.at/index.php?o2k-specifications] specifications of the OROBOROS O2k are based on the many unique instrumental features: 
{{MitoPedia O2k and high-resolution respirometry
 
|mitopedia O2k and high-resolution respirometry=O2k hardware, O2k-Open Support, O2k-Respirometry, O2k-FluoRespirometry
::* Critical selection of materials yielding a nearly [http://www.oroboros.at/index.php?backgroundcorrection diffusion-tight] chamber,
::* Long-term stability and linearity of the polarographic oxygen sensor ([http://www.oroboros.at/?O2k-POS POS]),
::* Highly automatic but transparent [http://www.oroboros.at/?O2k-O2Calibration calibration routines] and [http://www.oroboros.at/?O2k-Datlab-FluxAnalysis instrumental background correction],
::* Electronically controlled thermal environment with high temperature stability (+-0.001 °C),
::* Limit of detection of respiratory flux: +-1 pmol.s<sup>-1</sup>.ml<sup>-1</sup>.
 
'''B. Multiwell'''
 
::From their basic design, multiwell systems are a tool for qualitative '''high-throughput screening''', particularly for pharmacological testing.  In many cases, results are not strictly quantitative, but merely relative changes are obtained.  A high standard of quantitative results cannot be obtained with the present technology offered and advertised.  Huge oxygen fluxes reported by one group at a mitochondrial physiology meeting (MiPsummer School 2009, Baton Rouge, USA) were explained by a company representative as a "software problem". The '''absolute''' oxygen fluxes represent artefacts. More recently, the problems of high oxygen diffusion were recognized, but the large corrections render [[Talk:Rogers_2011_PlosOne#Instrumental_specifications_of_the_XF_multi-well_system_are_missing|non-specified errors in the calculation of background-corrected oxygen flux]].
 
 
==Accuracy of chamber volume and mixing==
 
'''A. O2k'''
 
::The 2 ml standard O2k-chamber volume is calibrated at <1% error (depending on calibrated pipettes), when inserting the stopper and filling the capillary at an error of <20 µl.
 
::The entire effective volume (excluding the injection capillaries) is accurtely obtained and well controlled stirring is provided in the O2k.
 
'''B. Multiwell'''
 
::No information is provided on the accuracy of the chamber volume in a multiwell system (~7 µl for the XF24).  This inaccuracy translates directly to the calculation of oxygen flux in the closed chamber. Similarly, accurate concentrations of titrated substances are not known. 
 
::Mixing by moving the sensor/injector part up and down a few times is inadequate. Undefined diffusion layers develop during a measuring cycle.
 
 
== Flexibility for MultiSensor applications ==
 
'''A. The modular concept of the O2k as a MultiSensor system'''
 
::The O2k is designed as a flexible modular system. The [[O2k-Core]] supports add-on modules, for simultaneous measurement of oxygen flux and
::* additional potentiometric measurment of mitochondrial membrane potential (ion sensitive electrode: TPP+), Ca2+ in solution (using the same ion sensitive electrode after mounting a different membrane), and pH.
::>>> more information @OROBOROS: [http://www.oroboros.at/?Membrane-Potential TPP and Ca]; [http://www.oroboros.at/?pH-Oxygen pH] - An oxygen flux of 50 pmol/(s ml) corresponds - at an assumed O2 flux to extracellular H+ flux ratio of 1:1 - to a pH change of about 86 µpH/s in a very weak buffer (2 mM).
::* additional amperometric measurement of NO or H2S. 
::>>> more information @OROBOROS: [http://www.oroboros.at/?NO-Oxygen NO].
::* additional fluorometric measurement of ROS production, membrane potential, Ca2+, ATP-production.
::>>> more information @OROBOROS: [http://www.oroboros.at/?O2k-Fluorescence O2k-Fluorometry].
 
::The DatLab software provides full flexibility for O2k-MultiSensor data monitoring.
 
'''B. Multiwell'''
 
::The XF system is restricted to the additional measurement of pH. No specifications are given on sensitivity [µpH/s] of the measurement of acidification rate. Until recently, the effects of buffers including the bicarbonate system have been ignored.  The rate of acidification was presented in pH units per time, ignoring the log scale of pH.  What is the drift of the pH signal?
 
 
== How are cell number or mitochondrial protein defined? ==
'''A. O2k'''
 
::In experiments with isolated mitochondria, tissue homogenates or suspended intact or permeabilized cells, the final concentration in the O2k-chamber is either defined by the preparation of the added suspension, and/or determined by taking a subsample from the chamber.  In this way, the measured oxygen flux (per volume) can be expressed accurately per unit of biological sample (per mg protein, per million cells, etc.).
 
::In experiments with permeabilized muscle fibers or other tissues, the tissue mass is determined before adding the sample into the O2k-chamber (e.g. 0.7 mg wet weight of mouse heart, 2 mg wet weight of human skeletal muscle), and the oxygen flux can then be expressed per tissue mass (mass-specific flux, reflecting mitochondrial density and functional quality).
 
::The flexibility of the DatLab-software allows on-line display of respiratory flux per unit sample (per mg, or per Million cells) or per volume of the aqueous medium.
 
'''B. Multiwell'''
 
::How many cells are actually in the closed compartment for measurement of respiration in a well, or which fraction of isolated mitochondria is outside versus inside the effective chamber?  How can the recorded change in oxygen concentration be converted to respiration per million cells or per mg protein? Without solving these problems, no quantiative measurements of respiration are possible.
 
== Are specifications comparable? ==
 
'''A. O2k'''
 
::There are [http://www.oroboros.at/?O2k-Specifications detailed and unique specifications for the O2k].
 
'''B. Multiwell'''
 
'''No specifications''' are given on sensitivity (lower limit of detection of oxygen; non-linearity and restricted linear range; detection limit of oxygen flux) in some multiwell systems.
 
 
 
 
{{MitoPedia methods
|mitopedia method=Respirometry
|type=Respiration
}}
{{MitoPedia topics|type=Respiration
}}
}}
[[Category:OroboPedia]]
[[Category:MitoPedia]]

Latest revision as of 09:37, 20 April 2021


                  


O2k-Open Support

O2k-Specifications



Template NextGen-O2k.jpg


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



Description

O2k-Info.png

O2k versus multiwell respirometer: O2k stands for Oroboros O2k and high-resolution respirometry, meeting powerful quality criteria securing high output and pioneering state-of-the-art comprehensive OXPHOS analysis of substrate control and coupling control of mitochondrial function. 'High throughput' stands for disposable multiwell systems - expensive, with limited scope and extremely high running costs. In respirometry, high throughput is not equivalent to high output. If you’re using a biased instrument, it doesn’t matter how many measurements you take – you’re aiming at the wrong target (Silver 2012 Penguin Press).


Reference: MiPNet18.10 O2k-Specifications, Flyer with specification summary


MitoPedia O2k and high-resolution respirometry: O2k hardware 


Questions.jpg




Combination of interests

Erich Gnaiger is founder and CEO of Oroboros Instruments, and responsible for the development of the O2k in collaboration with the O2k-Team and our partners. A series of methodological publications is the result of positive feedback between his work as faculty staff of the Medical University of Innsbruck, his company initiatives and numerous international cooperations.


Selected references

Comparison of respirometric methods -  Discussion
  • Horscroft JA, Kotwica AO, Laner V, West JA, Hennis PJ, Levett DZH, Howard DJ, Fernandez BO, Burgess SL, Ament Z, Gilbert-Kawai ET, Vercueil A, Landis BD, Mitchell K, Mythen MG, Branco C, Johnson RS, Feelisch M, Montgomery HE, Griffin JL, Grocott MPW, Gnaiger E, Martin DS, Murray AJ (2017) Metabolic basis to Sherpa altitude adaptation. Proc Natl Acad Sci U S A 114:6382–7. - »Bioblast link«
  • Lemieux H, Blier PU, Gnaiger E (2017) Remodeling pathway control of mitochondrial respiratory capacity by temperature in mouse heart: electron flow through the Q-junction in permeabilized fibers. Sci Rep 7:2840. - »Bioblast link«
  • Lemieux H, Subarsky P, Doblander C, Wurm M, Troppmair J, Gnaiger E (2017) Impairment of mitochondrial respiratory function as an early biomarker of apoptosis induced by growth factor removal. bioRxiv doi: https://doi.org/10.1101/151480. - »Bioblast link«
  • Gnaiger E, Boushel R, Søndergaard H, Munch-Andersen T, Damsgaard R, Hagen C, Díez-Sánchez C, Ara I, Wright-Paradis C, Schrauwen P, Hesselink M, Calbet JAL, Christiansen M, Helge JW, Saltin B (2015) Mitochondrial coupling and capacity of oxidative phosphorylation in skeletal muscle of Inuit and caucasians in the arctic winter. Scand J Med Sci Sports 25 (Suppl 4):126–34. - »Bioblast link«
  • Harrison DK, Fasching M, Fontana-Ayoub M, Gnaiger E (2015) Cytochrome redox states and respiratory control in mouse and beef heart mitochondria at steady-state levels of hypoxia. J Appl Physiol 119:1210-8. - »Bioblast link«
  • Makrecka-Kuka M, Krumschnabel G, Gnaiger E (2015) High-resolution respirometry for simultaneous measurement of oxygen and hydrogen peroxide fluxes in permeabilized cells, tissue homogenate and isolated mitochondria. Biomolecules 5:1319-38. - »Bioblast link«
  • Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. Bioenerg Commun:112 pp. »Bioblast link«
  • Pesta D, Gnaiger E (2012) High-resolution respirometry. OXPHOS protocols for human cells and permeabilized fibres from small biopsies of human muscle. Methods Mol Biol 810:25-58. »Bioblast link«
  • Votion DM, Gnaiger E, Lemieux H, Mouithys-Mickalad A, Serteyn D (2012) Physical fitness and mitochondrial respiratory capacity in horse skeletal muscle. PLoS One 7: e34890. |»Bioblast link«
  • Lemieux H, Semsroth S, Antretter H, Höfer D, Gnaiger E (2011) Mitochondrial respiratory control and early defects of oxidative phosphorylation in the failing human heart. Int J Biochem Cell Biol 43:1729–38. - »Bioblast link«
  • Pesta D, Hoppel F, Macek C, Messner H, Faulhaber M, Kobel C, Parson W, Burtscher M, Schocke M, Gnaiger E (2011) Similar qualitative and quantitative changes of mitochondrial respiration following strength and endurance training in normoxia and hypoxia in sedentary humans. Am J Physiol Regul Integr Comp Physiol 301:R1078–87. - »Bioblast link«
  • Scandurra FM, Gnaiger E (2010) Cell respiration under hypoxia: facts and artefacts in mitochondrial oxygen kinetics. Adv Exp Med Biol 662:7-25. - »Bioblast link«
  • Aguirre E, Rodríguez-Juárez F, Bellelli A, Gnaiger E, Cadenas S (2010) Kinetic model of the inhibition of respiration by endogenous nitric oxide in intact cells. Biochim Biophys Acta 1797:557-65. - |»Bioblast link«
  • Aragonés J, Schneider M, Van Geyte K, Fraisl P, Dresselaers T, Mazzone M, Dirkx R, Zacchigna S, Lemieux H, Jeoung NH, Lambrechts D, Bishop T, Lafuste P, Diez-Juan A, K Harten S, Van Noten P, De Bock K, Willam C, Tjwa M, Grosfeld A, Navet R, Moons L, Vandendriessche T, Deroose C, Wijeyekoon B, Nuyts J, Jordan B, Silasi-Mansat R, Lupu F, Dewerchin M, Pugh C, Salmon P, Mortelmans L, Gallez B, Gorus F, Buyse J, Sluse F, Harris RA, Gnaiger E, Hespel P, Van Hecke P, Schuit F, Van Veldhoven P, Ratcliffe P, Baes M, Maxwell P, Carmeliet P (2008) Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism. Nat Genet 40:170-80. - »Bioblast link«
  • Gnaiger E (2008) Polarographic oxygen sensors, the oxygraph and high-resolution respirometry to assess mitochondrial function. In: Mitochondrial Dysfunction in Drug-Induced Toxicity (Dykens JA, Will Y, eds) John Wiley:327-52. - »Bioblast link«
  • Hütter E, Renner K, Pfister G, Stöckl P, Jansen-Dürr P, Gnaiger E (2004) Senescence-associated changes in respiration and oxidative phosphorylation in primary human fibroblasts. Biochem J 380:919-28. - »Bioblast link«
  • Kuznetsov AV, Schneeberger S, Seiler R, Brandacher G, Mark W, Steurer W, Saks V, Usson Y, Margreiter R, Gnaiger E (2004) Mitochondrial defects and heterogeneous cytochrome c release after cardiac cold ischemia and reperfusion. Am J Physiol Heart Circ Physiol 286:H1633–41. - »Bioblast link«
  • Gnaiger E (2001) Bioenergetics at low oxygen: dependence of respiration and phosphorylation on oxygen and adenosine diphosphate supply. Respir Physiol 128:277-97. - »Bioblast link«
  • Gnaiger E, Méndez G, Hand SC (2000) High phosphorylation efficiency and depression of uncoupled respiration in mitochondria under hypoxia. Proc Natl Acad Sci U S A 97:11080-5. »Open Access«
  • Steinlechner-Maran R, Eberl T, Kunc M, Margreiter R, Gnaiger E (1996) Oxygen dependence of respiration in coupled and uncoupled endothelial cells. Am J Physiol Cell Physiol 271:C2053-61. - »Bioblast link«
  • Gnaiger E, Steinlechner-Maran R, Méndez G, Eberl T, Margreiter R (1995) Control of mitochondrial and cellular respiration by oxygen. J Bioenerg Biomembr 27:583-96. - »Bioblast link«



MitoPedia O2k and high-resolution respirometry: O2k hardware, O2k-Open Support, O2k-Respirometry, O2k-FluoRespirometry