DNA from agarose - home made spin columns?

[Mark Walberg]

This method has been published quite a few times-several 
times in Biotechniques for example.  
Just a few additions:
-If you have more than a tiny piece of agarose, you'll do 
better by using a 2 ml tube instead of a 1.5 ml tube.
-You don't need glass wool. You can use aquarium 
filtering wool, which is some kind of plastic that DNA 
doesn't stick to very much.  You can but a million year 
supply for $2 from any pet store. Use the tinyest 
possible amount of the wool.
- You don't really need to siliconize or sterilize your 
tubes.
-The needle hole doesn't need to be so big.  You can use 
a much smaller needle.  The DNA will be fine.
-I've never worried about removing the ethidium.  I don't 
think you need to either.  
-I've always frozen the gel slice after it is in the 
tube, but I have no idea if it helps.  It is easier for 
me to keep freezing them than it is to test whether or 
not it makes any difference.
Its easy, fast and cheap and it works.
walberg at simmons.swmed.edu