HELP! -- Protecting DNA on a transilluminator?
drm21 at mole.bio.cam.ac.uk
Mon Jul 7 14:40:14 EST 1997
In article <33c12035.5223697 at news.uchsc.edu>, Vern Shellman wrote:
>I am having problems ligating my DNA fragments cut out of a gel. I
>get variable results that seem to relate to how long it takes to cut
>out the band. The fastest I can see and cut out a band is about 15
>seconds and by then I suspect there is already significant UV damage.
>Is there any way to protect my DNA during UV exposure?
Use a LONG-WAVE UV transilluminator! If you haven't got a big long-wave
box, then use one of the little hand-help ones. (Of course, you might be
using long-wave already, in which case...):
I suppose you might gain a little time by attenuating the UV with
something, if you can't get hold of a long-wave source (but it'll be harder
to see the bands).
If you are purifying a LOT of DNA, and run the gel with a little ethidium
bromide in the gel and buffer, then you can often see the bands in daylight
against a white background. (This may also work with post-staining the gel,
but I haven't tried).
Alternatively, I think that the FAQ has methods for staining DNA without
using Ethidium bromide and UV - although it is less sensitive. The method
uses methylene blue IIRC.
D.R.Micklem, Time flies like an arrow...
Wellcome/CRC Institute, Fruit flies like a banana.
Cambridge CB2 1QR, UK Email:drm21 at mole.bio.cam.ac.uk
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