Terry:
If there is a good reason to desalt the whole preparation of oligo, it may
be worth the money for a PD-10 or a NAP column. If however, you need is
only for a tiny amount of oligo, what I do is to pack my own homemade
columns as I need them. To do that, I reuse my Pharmacia AutoSeq 1mL volume
spin columns, and pack into it a slurry of DNA grade sephadex G25 DNA grade
in water to give about a 400 uL bed. I would load a 20 uL sample. This way,
it cost me about 20 cents per run. We wash our used columns with soap,
water and methanol about once a month.
Hope it helps.
Tony
At 08:44 AM 5/3/00 -0600, Terry Mulcahy wrote:
>I tried the NAP columns when they were on sale, but I think they are too
>expensive. What is your "standard protocol", by the way?
>OPC columns from ABI, Glen, or other outfits can be used, but they are too
>expensive for routine desalting.
>I use the PD-10 columns, as they are a cheapest of all I've found. (If
>someone knows a cheaper way I'd like to hear of it.) I have equilibrated
>and eluted with either 20% ethanol, or water with good results.
>I got the 20% ethanol protocol years ago, but have never seen a reference to
>it, not why ethanol was used, unless it is a throwback to ethanol
>precipitation. Do you, or anyone, know of a reason why 20% ethanol is more
>useful for column desalting versus plain water? Terry M.
>
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>Terry Mulcahy
>DNA Synthesis:
>http://hsc.unm.edu/som/bmb/GenetAnal.html
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>>>> Thomas Billert <thomas.billert@jenabioscience.com> 5/2/00 >>>
>But sure, Sephadex is first choice for this purpose, we use
>Pharmacia's prepacked NAP columns (Sephadex G-25 DNA grade) with very
>good results here (using the standard protocol).
>
>Thomas Billert
>JenaBioScience GmbH
>
************************************
Anthony T. Yeung, Ph.D.
Director, Fannie E. Rippel Biotechnology Facility
Member, Institute for Cancer Research
Fox Chase Cancer Center
7701 Burholme Ave., Philadelphia, PA 19111
Voice: 215-728-2488 FAX: 215-728-3647 email: AT_Yeung@FCCC.edu
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http://www.fccc.edu/research/labs/yeung/
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