extract DNA using silica

[David F. Spencer]

In article <1f992a05.0301271023.2a76f2fb at posting.google.com>, 
jenc86 at hotmail.com (lin) wrote:

> Actually, if I have GuHCl, would the procedures still be the same
> except I replace NaI with GuHCl? Thanks.

You would have to use guanidine isothiocyanate (a.k.a. thiocyanate) 
because the binding of DNA to silica/silica gel requires a chaotropic 
salt, which NaI and GuITC are but GuHCl is not. Silica and silica gel 
gel are chemically both SiO2 but whereas the silica for Glass Milk-like 
protocols is just very finely ground SiO2 (sand or flint glass), silica 
gel is in a form with a more complex, porous structure.

Some of the Qiagen DNA purification protocols use silica gel with 
guanidine isothiocyanate.

Dave

-- 
David F. Spencer, PhD
Dept. of Biochemistry and Molecular Biology
Dalhousie University
Halifax, Nova Scotia, Canada

DSpencer at Dal.CA