I found protocols regarding working with either fresh or thawed ADP samples, from a perspective that it must be somewhat unstable in solution at above 0 degC.
If ADP is not chemically stable, what is the hydrolysis rate (at ~6 deg C)?
Hi Ziv,
From personal experience working with ADP (for example, in enzyme assays of creatine kinase) I'd offer the following advice:
- Freeze any aqueous solutions. Don't leave it in the fridge in a liquid state, no matter how cool your fridge is- the best manner of stabilizing it is freezing it.
- If you dissolve your ADP in simple water, the pH of that water may change dramatically depending on what ADP salt you're using. At the very least, try to dissolve your ADP in buffered solutions, even if the buffer is somewhat dilute, at neutral pH.
- Avoid adding divalent cations (e.g. Mg2+) if at all possible. That will tremendously speed up the hydrolysis of phosphodiesters, particularly ATP and also ADP.
- As with anything, avoid freeze-thaw cycles.
With these points, I was able to prepare large quantities of ADP solution, aliquot, and freeze them with no perceivable issues.
Good luck,
Chris
The rate depends on several conditions , for instance pH, Pi concentration, not onlt temperature .... it is difficult to say a value.
http://calzyme.com/commerce/catalog/spcategory.jsp?category_id=1013
Hi Ziv,
From personal experience working with ADP (for example, in enzyme assays of creatine kinase) I'd offer the following advice:
- Freeze any aqueous solutions. Don't leave it in the fridge in a liquid state, no matter how cool your fridge is- the best manner of stabilizing it is freezing it.
- If you dissolve your ADP in simple water, the pH of that water may change dramatically depending on what ADP salt you're using. At the very least, try to dissolve your ADP in buffered solutions, even if the buffer is somewhat dilute, at neutral pH.
- Avoid adding divalent cations (e.g. Mg2+) if at all possible. That will tremendously speed up the hydrolysis of phosphodiesters, particularly ATP and also ADP.
- As with anything, avoid freeze-thaw cycles.
With these points, I was able to prepare large quantities of ADP solution, aliquot, and freeze them with no perceivable issues.
Good luck,
Chris
- Badges
- Science topic