All of our dried substrates are either vacuum sealed or packaged under Argon atmosphere. The substrate in the unopened vessel is stable for at least 3 years if stored at -80ºC. Once dissolved in NanoFuel Solvent it will be stable for at least one year at -20ºC or below. We can’t guarantee the stability in a solvent of your choice (e.g. Ethanol, Methanol), since the auto-oxidation will depend on the water content of the alcohol and its overall quality.