DNA purification from Agarose (Sigma)

[Ian A. Boussy]

Mike Witty wrote:
>What I do is use TAE buffer, not TBE, cut out the gel slice and spin it
>through an eppendorf tube which has a TINY hole in it, plugged with glass
>beads.   ...
>   ...
>   ...   This method is not very efficient in terms
>of percentage yield of DNA, but is cheap and easy. 

Mike,

Why do you use glass beads to "plug" the hole??  Are these siliconized so that the DNA won't stick 
to them, or is this the source of your low percentage yield?

I've used siliconized glass wool, or, more recently, 100% polyester aquarium filter floss (see your 
local pets shop!).  The latter is from a suggestion in, I think, Biotechniques, to which I've lost the 
reference.  Several years ago I was able to estimate that I was getting on the order of 2/3rds of the 
DNA back.

Ian