Lambda DNA resists digestion
22313tcn at ibm.cl.msu.edu
Thu Nov 3 10:56:35 EST 1994
In article <396aas$ki1 at news.service.uci.edu>, rmauk at crick.bio.uci.edu (Rob
> I have isolated lambda gt10 DNA by PEG precipitation followed by organic
> extraction and ethanol precipitation, and find that it is almost
> completely resistant to digestion by EcoRI and all other enzymes that I
> have tested. Proteinase K treatment did not help, nor did additional
> extractions and precipitations. Plasmid DNA digests normally with these
> enzymes, but if the plasmid is mixed with the lambda DNA, it is rendered
> undigestable. Any comments or suggestions regarding the nature of this
> contaminant, or solutions to the problem would be greatly appreciated.
> Thank you.
I have found in many cases that the addition of spermidine to a final
concentration of 4 mM in the restriction buffer will allow the enzymes to
work. It is an easy test!!
MSU-DOE Plant Research Laboratory
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