Plasmid storage conditions - (Jun/23/2014 )
Is it still safe to use a plasmid kept in water in the 4C fridge for 1 year?
Safe for what? - you shouldn't catch any illnesses from it so long as it isn't visibly growing something,
The only way to tell if it is useable is to run some on a gel and look at its integrity.
Depending on application, you might be better off transforming and doing a fresh prep.
yes, check it's integrity on a gel. it may have been acid hydrolyzed by the water (after absorbing co2 from the air).
If it was stored in TE rather than water, I'd say it is likely fine. If in water, then I would have doubts. Almost certainly you could transform it, which is what I would do immediately, then do a new prep.