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I am trying to identify the best way to measure glucose concentration in culture media with E. coli. Now, I imagine I can use those glucose meters that diabetic people use, but unfortunately can't find any papers as background. Any ideas would be appreciated.

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  • $\begingroup$ you definitely cannot measure media glucose concentration with a blood glucose analyzer - see this link for more information on that... biology.stackexchange.com/q/20325/16299 $\endgroup$ Apr 13 '16 at 16:44
  • $\begingroup$ there are a number of colorimetric assays that are commercially available - we routinely measure plasma and other fluid glucose concentrations using a single reagent method and a standard curve - you just need a UV/Vis reader and some reagent which is inexpensive $\endgroup$ Apr 13 '16 at 18:31
  • $\begingroup$ Thank you Vance for taking the time to reply. As you can probably tell, it's my first day here! $\endgroup$
    – user23198
    Apr 13 '16 at 22:03
  • $\begingroup$ @VanceLAlbaugh, It think it's possible to measure glucose concentrations in pretty much any solution with a blood glucose analyzer. But you need to recalibrate the signal since the typical assumption of the instrument are no longer valid. Just do a standard curve of known glucose concentrations in medium. We have done this before with blood glucose analyzer and I think it works well. These analyzer are just a glucose oxidase kit in miniature, they are no better or worse than other enzymatic methods in my experience. $\endgroup$
    – Roland
    Apr 14 '16 at 5:41
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The most common method of measuring glucose concentrations (in pretty much any sample) is an enzymatic assay based on the glucose oxidase enzyme. This method is reliable because the enzyme is known to be quite specific for glucose; it does not oxidize fructose, galactose, or any of the other common hexose sugars which can contaminate many other measurement methods. The enzyme can be coupled to other reactions so that the amount of glucose oxidized can be read out by a standard spectrophotometer. There are many kits commercially available based on this principle, like this one. A review of glucose oxidase from the glucose measurement perspective is found here.

Blood glucose analyzers are also based on glucose oxidase. Typically, they have disposable slips that contain glucose oxidase along with some electron-carrying chemicals that convert enzyme activity into an electrical current sensed by the device. It is possible to measure glucose in pretty much any solution with such insruments, but as mentioned in comments, you need to make a calibration curve for glucose in your solution of interest (culture medium, or whatever), as you cannot trust the readings from the instrument directly when measuring under different conditions. We have previously used this approach to measure glucose in mammalian cell culture medium, and it works fine in our hands.

It is also possible to quantify glucose by mass spectrometry or nucleic magnetic resonance methods, but unless you have such a facility and expert help, I guess that is not an option in this case.

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