Freeze and squeeze

Michael Kloth mtkloth at
Wed Feb 22 20:42:28 EST 1995

celer at (Celer Vladimir) wrote:
> Hello,
> I need to recover the plasmid DNA ( 6000 b.p.) from agarose gels.
> What is the freeze and squeeze method? What are the advantages of this method
> over phenol-chloroform extraction? Can you help me?
> Thanks fot the help.

Quite simply, you cut out the band of interest and put it
onto a piece of parafilm.  Freeze the band for 20-30 min
at -20, then melt the gel between your fingers, collecting
the DNA in a clean eppendorff tube.  The only things to look
out for are 1) wear gloves, 2) use a TAE buffer system (the 
acetate for some reason enhances recovery) and 3) use a low
melting point agarose.  After collecting the DNA, precipitate
it using potassium acetate and ethanol.

All  in all, it is simple and easy.  A typical yield is 
between 60 and 80%.

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