ATP is much more stable than most people think. In the attached paper 2 (Applied Microbiology 30, 713-721) it is shown that ATP in extracts from E.coli cultures prepared with TCA is degrade by

ATP is not stable in strong acid. At room temperature it is rapidly degraded (within minutes). Even on ice ATP is hydrolyzed albeit more slowly. See accompanying paper

Thanks, Alfred. From the paper I understand the neutralised extract should be fairly stable if frozen, correct?

That is right! If you want to obtain information on the precise recovery you can allways add internal ATP as a standard. Take care that you do not get local alkalinization upon neutralization of your samples. ATP is also very unstable in alkaline milieu. Use the Vortex (and samples on ice) when you neutralize the samples! Use a buffer (e.g. Hepes, together with, e.g., KOH if you want to use KOH to neutralize the samples) to avoid large changes in the neutral pH region. Be aware that KClO4 precipitates during neutralization (no precipitate will be formed with TCA).

ATP is much more stable than most people think. In the attached paper 2 (Applied Microbiology 30, 713-721) it is shown that ATP in extracts from E.coli cultures prepared with TCA is degrade by

Thank to all by the discussion and contributions!

In any case, use internal standards and you will obtain the proper information on the stability of ATP under your particular experimental conditions!

Dr. Meijer provide very interesting results showing that ATP is very unstable in PCA extracts. My own results in the papers already provided (cf. my previous answers) suggests that ATP is fairly stable. Obviously the sample composition and the extraction procedure have a considerable influence on the stability. A special problem is co-precipitation of ATP with high concentrations of extractants, especially when precipitating KClO4. For this reason I prefer quats like dodecyltrimethylammonium bromide or TCA in optimized concentrations.