The method can be applied to most enzyme-catalysed reactions. The apparatus & methods presented here overcome the drawbacks that have prevented this method from being more widely used in the past.
Reactions that are easily measured are:
HYDROLASES - where there is an ionic product
More difficult would be DEHYDROGENASES, although there is no change in the number of ions there is a change in mobility of the ions, [e.g. from NADH to a proton], so this may well be measurable. Spectroscopy will remain the favourite method for these enzymes I think.
ISOMERASES & TRANSAMINASES look unsuitable for this method
The technique is easy to use and could be applied for clinical tests [with the exception of glucose], which has been 'solved' with inexpensive miniaturised sensors and readout systems - brilliant!!
The same technology could easily be applied to more generalised measurements of the enzymes described above. The main problem I forsee is the shrinking of the temperature control system which needs to be accurate for the measurement of rates of reaction. The enzyme can be added as a reaction component or, as in the glucose detectors, be attached to the electrode surface, so that only the substrate and buffer need to be added.
The apparatue as presented here is ideal for school/ college research projects & it could be commercialised using modern minitiaturisation methods for widespread use in CLINICAL TESTING, not only in a lab setting but most importantly in the FIELD, since it is easily transportable, e.g. on a bicycle.
HAVE A GO YOU WILL FIND IT FUN!
CLINICAL TESTS FOR BLOOD USING THE CONDUCTIVITY METHOD
Creatine kinase XX
Lactate Dehydrogenase X
Alkaline phosphatase XX
Angiotensin Conv. Enzyme XX
Number of X's indicates sensitivity, assessment is based on ionic (& mobility) change upon reaction. Glucose is excluded as excellent inexpensive kit is available.