I made a DTT stock a few days ago and stored it at -20ºC, and when i defrosted it, it seems unable to dissolve in the solution and has a clear white color.
Hi there,
Solubility varies with temperature. I notice this phenomenon everytime I thaw my 0.5M stock solution (further incubation at room temperature allows the dissolution of the precipitate).
Hi there,
Solubility varies with temperature. I notice this phenomenon everytime I thaw my 0.5M stock solution (further incubation at room temperature allows the dissolution of the precipitate).
- At -20C DTT @ 1M is stable for years; in the absence of freeze thawing
- Sometimes what you describe can happen
- If you simply thaw between your hands andf then vortex or warm to 37C it will probably go back into solution
I keep it in cold room and it lasts. Mine is still there after 2 years and still it works.
Definitely DTT is stable for years... But it is important to keep the tubes well closed and avoid freeze thawing cycles. It is therefore recommended to make small aliquots and store them at -20°C.
What I do is make small aliquots of 1M DTT and store them in -20 degree C. Avoid multiple freeze-thaw cycles and it should be fine for years. I still use some that are close to three years old and they are working fine. In case your sample seems white after thawing just warm it up in your hands and vortex it for a short while.
Hi Nicolaas, if even after thawing by all proper means you still observe some precipitates, so this DTT cannot be used in such case. You need to prepare fresh one. May be the concentration you are using was not dissolved well at the time of preparation.
Recommendation to use DTT is prepare fresh one as possible, as it is not much stable in solution form & if it does not suite then storing its aliquots at -20 C is also fine.
Regards...
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