4-MUG stability - in -20 over 15 years (Apr/20/2011 )

Hello,


I need to use 4-methylumbelliferyl-b-D-glucuronide (4-MUG) for an enzyme assay. We have some in our freezer that is 15 years old (powder form). Would 4-MUG that old still be usable?

I believe that the methylumbelliferyl moiety is stable so you may just have a increase in background signal which generally wont cause any problems (unless you are measuring product inhibition).
A quick test by dissolving some and measuring against standard will sort it out.