matrix for spin columns
Paul N Hengen
pnh at ncifcrf.gov
Wed Mar 26 12:35:55 EST 1997
Michael Benedik (benedik at uh.edu) wrote:
> Can anyone suggest a suitable matrix for making homemade spin columns
> to separate PCR products from primers. Exclusion should be larger than
> 50nt or so.
Mike:
Try Sephadex G-50 (cut-off is ~ 30,000 MW). The MW of a 50 nt PCR product will
be close to 30,000 if it is 0% CG or 100% GC (all A's or all C's). If you find
it too close for the cut-off try Sephadex G-25. You can get it from Sigma (see
page 1813), or you can buy pre-loaded push columns from other biotech companies
like Stratagene...very convenient.
Using the dnamwt program gives you the MW of the PCR product,
All A's:
dnamwt 1.08
the number of A's in strand 1 of the sequence is: 50
the number of C's in strand 1 of the sequence is: 0
the number of G's in strand 1 of the sequence is: 0
the number of T's in strand 1 of the sequence is: 0
total number of bases: 50
strand 1 molecular weight: 15678.0 daltons
strand 2 molecular weight: 15228.0 daltons
total molecular weight: 30906.0 daltons
% GC: 0.0
OR
All C's:
dnamwt 1.08
the number of A's in strand 1 of the sequence is: 0
the number of C's in strand 1 of the sequence is: 50
the number of G's in strand 1 of the sequence is: 0
the number of T's in strand 1 of the sequence is: 0
total number of bases: 50
strand 1 molecular weight: 14478.0 daltons
strand 2 molecular weight: 16478.0 daltons
total molecular weight: 30956.0 daltons
Also, if you want the dnamwt program written in pascal, I'll send it to you.
--
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* Paul N. Hengen, Ph.D. /--------------------------/*
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