Storage life of plasmid DNA in water - (Dec/13/2013 )

How long can I store plasmid DNA reconstituted in water for? I still have the mushed up blotting paper in the tube together with some DNAse free water.  Storage conditions: 4 degrees C (or should I store it at -20?)

If you plan to use it much later (say after a week or so), -20 is the way to go, otherwise, 4 degrees should be fine. 

Ameya P on Fri Dec 13 08:43:49 2013 said:

If you plan to use it much later (say after a week or so), -20 is the way to go, otherwise, 4 degrees should be fine. 

What would be the best way to store palsmid DNA? (A) In it's original state in a tube (since everytime you only need a few microlitres for transformation), (B) Transformed competent cells on agar plate, (C) Transformed competent cells in glycerol or (D) plasmid prep after transformation?

I'd recommend both C and D.

Water is actually a bad choice for storing DNA. Use TE instead -- the Tris buffers at basic pH for better DNA stability, and the EDTA removes magnesium, a required cofactor for DNAse enzymes.

phage434 on Fri Dec 13 12:21:14 2013 said:

I'd recommend both C and D.

 

Water is actually a bad choice for storing DNA. Use TE instead -- the Tris buffers at basic pH for better DNA stability, and the EDTA removes magnesium, a required cofactor for DNAse enzymes.

what composition of glycerol should i use? 50%? or 10%? in LB?

15% glycerol in an LB culture is a good start.