CHEF gel problems

Rafa Maldonado rafael at
Mon Jan 10 22:29:50 EST 1994

Hi Rick:
The only thing you can do is increase the pulse times of the CHEF, to
get into the gel bigger pieces of DNA. I think the problem is that your
plasmids are too big for getting into the gel and they stay in the
well, in the settings that you're using. Don't worry about the
chromosome, it is enough big to don't enter into the gel.
Anyway, I lack some important information about you stuff: the size of
your plasmids. But in this way I think can work, if there is enough
difference of molecular weight between your plasmids and chromosome!
Other alternatives (I don't like them) are reduce the concentration of
agarose, reduce the voltage in the running and increase the total time
of the electrophoresis.

Rafael Maldonado
Howard Hughes Medical Institute
University of Utah
Salt Lake City, UT
rafael at

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