Stability of ATP (to hydrolysis) is pH dependent, and even the disodium ATP
is strongly acidic in distilled water. I used to make 100 mM ATP by
dissolving disodium or Na,K-ATP in ~100 mM NaOH, getting pH ~6-7.
This suggests 8.3 would be better:
http://www.patentstorm.us/patents/6916616/description.html
Also, the standard phosphate assay hydrolyzes ATP pretty rapidly, so
people measuring ATPase use a special assay with milder conditions-
names like Fiske-Subbarow and Lohman-Jendrassick come to mind, but
not sure if either is the one suitable for ATP.
No I think it was the Lowry-Lopez method which uses ascorbic acid
at pH 4 instead of ANS as the reducing reagent.
dengzq1987 wrote:
> Dear all,
> recently, i prepared the ATP solution used to assay ATPase activity.
> when the Control Well just containing assay buffer and ATP mixed with
> molybdate ,the colour changed to green, this mean that there is free pi
> in the
> solution.the assay buffer and water is free from pi.and the ATP stock
> solution has free pi ,maybe the ATP hydrolysis when prepared .any
> suggestion about preparing ATP stock solution is appreciative.
> Best regards!
> 2010-08-29
> ------------------------------------------------------------------------
> dengzq1987
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