DNA probes for use with prokaryote DNA in Southerns

Douglas Easton dpeaston at wzrd.com
Wed Dec 18 20:21:33 EST 1996

My usual procedure for making probes from plasmid clones is to cut the
insert from the vector and gel purify the insert for labeling and use as
a probe for Northerns or Southerns. Recently I have atttempted to
identify prokaryotic homologues to eukaryotic sequences. I find that
even after 2 cycles of gel purification, the vector sequences seem to
hybridize to the 1 KB ladder that I use in my gels. This ladder is a
concatemer of a PBR/PUC derived plasmid. The vector I am using is

Any suggestions for avoiding this problem?

-Doug Easton

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