How long are glycerol stocks viable? - (Aug/19/2005 )

I was wondering how long are E.coli and Agro strains viable in Glycerol Stock? I am currently in the process of updating all of our lab stocks. I have heard 2 years for E.coli but I am not sure about Agro?

If the glycerols are stored at -80 and have not been thawed and refrozen many times, they are viable for many many years. I have samples in my freezer that trivially are recovered after 7 years, but my colleagues have much older samples which are still viable. At -20, the lifetime is probably much shorter. I can't speak for the Agro cells, but I would be surprised if they were substantially different.