phage434, on May 21 2009, 06:55 AM, said:
The cells on those plates are almost certainly dead. For long term storage, grow cultures of your cells in LB or another rich medium, add sterile 80% glycerol solution to give a final 15% glycerol concentration in your medium, and freeze at -80C for storage indefinitely. If you are desperate to recover a plasmid from your (now dead) cells on the plate, it might be possible to prep DNA and transform living cells from your colonies, but I would not count on it. Storing plasmid DNA is also an effective means of long term storage.
yeah, i agree with that. i myself have tried to revive colonies from a month old plate, it did not work....i wouldn't rely on such an old plate.