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Cleaning metal forceps and spatulas of DNA???

Alexander Kraev kraev at bc.biol.ethz.ch
Fri Nov 17 11:51:32 EST 1995

> >       I am doing a lot of PCR which requires absolutely no contamination
> > from one prep to the next, and also I am doing library screening.  To
> > eliminate contaminating DNAs (especially from different species) I use
as much
> > disposible plastic-ware as possible, I acid wash (fresh 1:10 HCl overnight)
> > glass, but there are some things (metal spatulas and ceramic mortar and
> > pestles, as well as the metal/teflon pestle from a dounce homogenizer)
> > cannot be thrown away nor can they be acid washed.

If one recalls DNA chemistry, a 1 hour incubation in a 0.1% solution of an alkylating agent, followed by hot 0.1 M alkali for 15 minutes should destroy DNA to dust ( e.g. short oligonucleotides ). So the question is really about alkali resistance of a given material, rather than to acid. I never had the problem of eliminating all traces of DNA, but had it come to that, I  would have tried 0.1% dimethylsulphate or diethylpyrocarbonate for 1 hour, and then 60 C alkali for 15-60 minutes.

Hope this helps,

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Alexander Kraev, PhD                     Internet:    kraev at bc.biol.ethz.ch
> Lab.of Biochemistry III                            Phone:      0041-1-632-31-47
> Swiss Federal Inst. Of Technology      FAX:           0041-1-632-12-13
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