0
$\begingroup$

I am going to use adult Drosophila to do an ATP assay (ATP determination kit A22066). The most convenient for me is to freeze the samples and perform the experiment later.

However, the protocol provided by the kit producer keeps saying the assay is extremely sensitive, so I'm not sure if it's okay to keep the homogenized samples under -80°C for a short period of time.

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ you'll never know for sure unless you run some fresh and run some after freezing - might not be worth the risk $\endgroup$
    – Vance L Albaugh
    Commented Feb 17, 2017 at 21:22

1 Answer 1

Reset to default
1
$\begingroup$

Pure ATP can be stable when stored frozen but I would be worried, perhaps unjustifiably, about storing a homogenized sample. You should try dividing a homogenized sample in half and assaying one half right away and the other half after freezing to see how the signals compare.

Improve this answer
$\endgroup$
6
  • $\begingroup$ Could you elaborate why storing a homogenised sample should be worrying? $\endgroup$
    – Arsak
    Commented Feb 18, 2017 at 12:57
  • $\begingroup$ @Marzipanherz I would be worried, perhaps not justifiably, about controlling pH and ATPase activity. $\endgroup$
    – canadianer
    Commented Feb 18, 2017 at 19:10
  • $\begingroup$ I was told that there is no (noteworthy) enzyme activity at -80°C. However, I just took this for granted... Guess it's time to find a reliable source for this :) $\endgroup$
    – Arsak
    Commented Feb 18, 2017 at 19:20
  • 1
    $\begingroup$ @Marzipanherz My supervisor once told me that he was working with a colourimetric substrate that turns from clear to purple during some enzyme-catalyzed reaction. He prepared a stock solution, clear in color, and froze it overnight. The next morning it was purple, presumably due to trace enzyme contamination. There's also the time spent while freezing and thawing it but, again, my concerns may be unfounded. $\endgroup$
    – canadianer
    Commented Feb 18, 2017 at 23:10
  • $\begingroup$ That's really interesting! Thank you for sharing! $\endgroup$
    – Arsak
    Commented Feb 19, 2017 at 10:03

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .