Does anyone have any suggestions for suspending and storing elastase in aliquots and the how long it can be stored like this for? Many thanks

For long term storage lyophilization and storing it cold is probably the best. It still has decent activity after ~6 months and more. If you want to store it in solution use a alkaline buffer ~pH 8, avoid glass wares, as it readily adheres to it. If it is only for a couple of days I'd store it at 2-4°C, as freeze/thaw cycles rapidly reduces elastase activity (true for all proteins).

thank you. It comes as a lyophilized powder (1 unit) and I was advised by the company to suspend it in saline below pH6 and preferably at pH5.3 which I did but I have no activity. Thanks for your advice - will definitely look at that.

Sorry, I have to retract part of my statement. I remebered using a pH 8 buffer at one point, but it wasn't my storage buffer.

Elastase has a higher solubility and activity at alkaline pH (that's when I used a pH 8 buffer), but for storage I also used a buffer around 5.5 in order to avoid activity loss.

So ideally store it as powder. After resuspending it, you should aliquot it (for one assay each) and store at -20°C which should work for at least a month (if memory serves). At 4°C it loses activity after a week or so (in my hands).