Using 4-year old precast gels - (May/24/2012 )
Are there any possibilities in using a 4-year old precast gel? I've ordered some in but just want to run a pilot experiment for the time being and coincidentally found some bought by previous students.
What is the worst case scenario in using an expired Tris-HCl gel?
And what is the best case?
Worst case scenario - The gel doesn't resolve your bands.
Best case scenario - it does
If it's just a pilot experiement with samples that you can either regenerate or are of low value then run them on the gel along with some known good samples (and ladder) and see.
But first, take the gel out of the packaging and make sure that it looks good, isn't awash with buffer that's leached out of the gel.
Given that the gel looks okay and then gives good resolution of our known samples and ladder then that one gel is good.
If not then not.
Probably the thing that's going to go wrong, if it does go wrong, is that the concentration of tris-HCl in the gel will decrease so that there's a difference between running buffer concentration and gel concentration which would affect the running of your gel giving poor resolution and altered running times.
But if you have time give it bash. Or, just wait for the delivery of something that should work first time.
are their continuous or discontinuous gels? Discontinuous I would through away....
ok, final verdict: the gel is all crumpled and dried up. So much for free commercial leftover gels in the lab.
I have kept my precast gel (Invitrogen) in the cold room (4 C) and some of them is 2 year old after expired date...it still works for me.