5-Aza - Stability in DMSO - (Dec/30/2005 )

Hi, does anyone know or has anyone had experience with 5-aza stability in DMSO. I was having some nice results in Oct now its not as good in late Dec. I have the 5-aza in DMSO at -80 (a pretty popular spot in the freezer), its in 2ul alloquats and I use a new tube for every experiment. Its either my cells or the 5-aza. The final possiblity is that im retarded (very possible).

Thanks in advance.

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I am going to do the same kind of experiment, and I called Sigma tech support, they said that the 5-aza is very unstable, you should make it fresh everytime! I am very skeptical about that. Seems from your post, you can keep it in liquid as for stock for a while, could you pls tell me more details about the storage condition of your stock? (in DMSO, what concentration? How much you used for your cell final conc.? did you try 50%acetic acid? can it keep like in DMSO?)

Thanks!

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I think you can keep it in liquid stock for about a month. This is at -80 in DMSO. I made my stock 5-aza solution according to the sigma protocol, 50mg/mL or 0.219mol/L. I aliquoted (2ul) and used a fresh tube each time. I would have been done these experiments some time ago, however, I ran out of antibody and now I believe the drug is breaking down.

When you start your experiment do a concentration gradient to see the best concentration of 5-aza for your cells. Lower concentrations worked better for me.

Good luck.

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Thank you for your replay.
I called Sigma, and the tech support said the stock conc. for DMSO should be "10mM" at -80C, he said he can't find the info of how long can be kept. He said the 50mg/ml is only the optimal conc. they tested. I don't know if that will make a difference.
I am trying the conc. Thank you.

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