Glowing Blue DNA Gels

Jason Rancourt aq780 at FreeNet.Carleton.CA
Thu Apr 28 22:53:20 EST 1994



In a previous article, djt2 at po.cwru.edu (Dennis J. Templeton) says:

>In article <2on8f0$gcv at news.doit.wisc.edu>, skralyf at cae.wisc.edu (Frank
>Anthony Skraly) wrote:
>
>> What the . . . ?
>> 
>> The last 2 times I ran agarose gels (TAE buffer, stained in dilute ethidium
>> bromide/water), I put them on the UV box and they glowed 
>> 
>> 	BRIGHT BLUE ALL OVER.
>> 
>> This made it very difficult to see the orange EtBr/DNA bands. 
>> 
>>
>Can you say autofluorescence? Try pouring a gel without EtBr and it will
>also glow bright blue, I bet. We have seen this twice, once while trying to
>run a 5% gel (the consistency of a superball) and another time with some
>el-cheapo agarose at 1%. I can't recall the brand, name... Gell-O maybe?
>Anyway, the odds are good that it results from a contaminant of the agarose
>that is not significant at *normal* concentrations of your routinely good
>agarose. 
>
>BTW, you might try viewing with long wave instead of short, or vice-versa.
>I recall that long wave showed the effect less, though I might have this
>reversed.
>-- 
>Dennis J. Templeton
>CWRU School of Medicine
>
Another reason for bright blue gels is that you might be overheating your
agarose if you're melting it in the microwave, and its degrading into
bitty autoflorescent monomers. A solution is to nuke it only to the boiling
point and then swirl to dissolve the chunkies. Also, only make agarose in
small batches so that when you get to the agarose dregs it hasn't been
nuked a hundred times.

Jason Rancourt
University of Waterloo
-- 
______________________________________________________________________________
Jason Michael Rancourt      *  Because for thy sake I have borne reproach
aq780 at FreeNet.Carleton.ca   *  shame has covered my face. (PSALM 69)
______________________________________________________________________________



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