Unwanted DNA degradation by addition of restriction enzyme buffer

[Sven Even F. Borgos]

Magnus Sundstrom wrote:
> Hi
> 
> Anyone experienced degradation of plasmid DNA after addition of the
> restriction enzyme buffer. Why is it happening and how can it be
> avoided?? I get a smear on the agarose gel and it is enough to add the
> buffer to get this. Very frustrating...
> 
> Thanks for your help / magnus
> 
My bet would be nuclease contamination of your buffer - could occur e.g. 
if you happen to mess around with bare fingers (no gloves). Anyway, the 
easiest thing to do is use a new tube of buffer and throw the old one 
away - you probably have several of these.

Sven Even
NTNU