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[GradMom]

I'm making up plates with 3-Amino-1,2,4-triazole, aka 3-AT (super tricky and time consuming plates ). I'm getting some unexpected results (not necessarily bad results, but weird) and I want to rule out the possibility that I'm mistreating the 3-AT.

Does anyone out there use it regularly?!

I've checked the literature. I've searched google. I've spoken with tech support at Sigma. I can't find any information regarding the typical storage conditions of 3-AT. I've got it at 1 M in water, filter sterilized and stored at -20. Is this pretty standard? How long is it good stored at -20? Should I be making small aliquots to avoid freeze-thawing? I thaw it in a room temperature water bath. Should I be making it up fresh? For the plates I'm making, I add the 3-AT to a solution of non-autoclavable reagents, filter sterilize, and bring it up to about 50 C. I then add that solution to an autoclaved agar solution that's at about 50-60 C. Is this OK? Is 3-AT stable at 50 C? For how long?

Any info would be GREATLY appreciated!!

[GradMom]

In an answer to my own question, just in case anyone else is wondering about the stability of 3-AT.

Santa Cruz Biotechnology says:
3-AT is soluble in hot water up to 50 mg/mL (which is about 0.59 M). Interesting, because I was able to get it into solution at 1 M with only a little heat.
They also recommend making small aliquots and freezing them at -20. They say it's stable up to 3 months at -20.
http://www.scbt.com/datasheet-202016.html

Sigma gave me this:
The product is soluble in water, methanol, ethanol and chloroform, and sparingly soluble in ethyl acetate. It is insoluble in ether and acetone. Aqueous solutions are neutral.

I also found a reference to unpublished data amongst some herbicide info. It says the following:
The stability of amitrole (3-AT) was studied in buffer solutions at 90C at pH 4,7, and 9 and a concentration of about 10 mg/L. Samples were taken 0, 19, 94 and 114 days after application. No degradation was observed, indicating that the half-life of amitrole in water at 20 C would be more than one year.