Warburg manometry

Activity can also be followed conveniently by measuring O2 utilization with a recording O2 electrode. This procedure is as sensitive as the spectrophotometric method, as simple to perform, and can be used with solutions that would be optically unsatisfactory in the spectrophotometer. Measurement of O2 consumption by Warburg manometry should be avoided. Not only is it cumbersome and less precise, but lipoxygenase, especially when somewhat purified, is highly sensitive to surface dena-turation on shaking. 

Introduction of photoelectric cells led to the replacement of the Duboscq colorimeter and so to quantitative spectrophotometric methods of analysis which met biochemical requirements. This introduction of spectrophotometry as a routine procedure was one of the earliest technological advances underpinning the elucidation of biochemical pathways between 1930-1960. Micromanometric methods also became available about the same time, and offered a means to measure cell respiration. Manometry was developed in Warburg s laboratory in Berlin and was one of the main techniques used by H.A. Krebs in his studies on the citric acid and urea cycles (Chapters 5 and 6). 

For reactions in which one or more reactants or products is a gas, manometry (the measurement of pressure differences) can provide a convenient means for monitoring the course and kinetics of the reaction Thus, enzymes that can be assayed with this method include oxidases, urease, carbonic anhydrase, hydrogenase, and decarboxylases. For example, bacterial glutamate decarboxylase is readily assayed by utilizing a Warburg flask and measuring the volume of gas evolved at different times using a constant-pressure respirometer. ... 

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