Is 260:280 ratio good for oligos?

Richard V. Giles giles at liv.ac.uk
Wed Sep 16 02:45:10 EST 1998



Rich Dudley wrote:

> I purchased some oligos, and haven't had any success at PCR.  Controls
> pointed to the oligos as the problem.  I extracted the oligos twice with
> n-butanol, and EtOH precipitated, and resuspended.  I quantitated at
> 260, but out of habit, I also took the 260:280 ratio.  Were these
> midipreps, I would throw out the DNA and start over--ratios ranged from
> 1.1 to 1.4.  Does the 260:280 definition of "clean" hold for oligos, or
> are these oligos probably ok to use?
>
> Thanks!
> rich
>
> --
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Rich,

Your oligos aren't necessarily up the creek. Oligo dT would have a maximal absorbance at ~267nm.

Check out Maniatis "Molecular Cloning" ppC4-C12 for millimolar absorbtivities and max abs
wavelength.

Cheers.


--
Richard V. Giles Ph.D.
School of Biological Sciences
University of Liverpool
Tel +44/151 794 4389
Fax +44/151 794 4349
http://www.liv.ac.uk/~giles/





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