purify PCR products using Wizard Prep (Promega)

dkim at unm.edu dkim at unm.edu
Wed Jun 29 09:13:17 EST 1994

(Omitted query re:gel purification and reply thereto)

The Wizard prep is basically a glass adsorption method similar to Geneclean, 
except that guanidine thiocyanate is used instead of sodium iodide. The
Geneclean instructions state that there is much lower recovery of small
DNA fragments. This may also be true of Guanidine thiocyanate based adsorption.

I would guess that the guanidine thiocyanate solution may solubilize
agarose about as well as sodium iodide does (place gel in solution at 50 C
for a little while and see.). You might want to check out the PNAS paper by
B. Vogelstein and D. Gillespie which describes Geneclean-like procedure (
it is cited in the GEneclean literature) for other parameters that may be of

Finally, people often get acceptable yields using straight physical methods
for DNA from gel purification, such as freeze and squeeze, etc. You might want
to check out a very quick and dirty method in BioTechniques (sometime this
year) in which the gel slice is simply pushed through a 0.45 micron syringe

Daniel Kim

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