pH and Oxygen


Bioenergetics: Classical studies on bioenergetics used the simultaneous measurement of O2 and pH, particularly in the context of the discovery of the chemiosmotic coupling mechanism, and quantification of H+/O2 stoichiometric ratios for proton pumping (Peter Mitchell).

Cell physiology: Aerobic glycolysis in intact cells can be quantified by measurement of proton production as an indirect but continuous record of lactate production and corresponding acidification of the medium, while simultaneously monitoring oxygen concentration and oxygen consumption. In a well buffered culture medium, the pH change is extremely small relative to the amount of protons (lactic acid) produced, hence a low-buffering capacity medium needs to be applied. A titration of acid (lactic acid or HCl) into the low-buffering capacity medium yields the pH-dependent buffering capacity (Delta H+ added/Delta H+ measured by the pH electrode). Under various metabolic conditions, lactic acid production is the dominant mechanism causing acidification, hence the pH measurement is a good indirect indicator of aerobic glycolysis. 


pH Systems


Oroboros Instruments offers highly sensitive pH systems (stoppers, electrodes, special connectors if necessary) that can be used together with any oxygraph equipped with a multisensor upgrading.

Please consider the limited lifetime of the pH electrode before placing your order.

Combining a pH electrode with the TIP2k allows to use a pH stat approach, keeping the pH value constant while measuring proton flow in weakly or un-buffered medium. The measurement of proton production under high-resolution conditions introduced some unique challenges for the design of an experimental protocol and subsequent calculation.

For more and up to date information see this article about the pH electrode and measuring proton flux on our wiki type page its corresponding discussion page.

See also:

Protocols: pH measurement and temperature dependance of pH. MiPNet08.16


Excel Templates (including instructions for use):

  • pH Stat Template Buffer Capacity_one_point(filled) [download 60 kb]
  • pH Stat Template Buffer Capacity_one_point.xls [download 55 kb]
  • pH Stat Template Injected Volume(filled).xls [download 356 kb]   
  • pH Stat Template Injected Volume.xls [download 28 kb]   

DLTemplates can be imported for TIP2k-Setups.

        For downloadingclick on the file name and save to C:\DatLab\DLTemplates. 


        For importing DatLab Templates, open DatLab, choose "File" in the   

        DatLab Menu, choose "Import" and "DatLab Templates", go to

        C:\DatLab\DLTemplates and select "DLTemplates_pH.dlt".


to topPrint page


OROBOROS High-Resolution Respirometry