Supercoiled DNA

Darren Boehning boehnin1 at
Tue Aug 18 11:55:38 EST 1998

Has anyone noted plasmid DNA no longer being supercoiled?  It seems that 3
of my plasmids (all about 15kb) are no longer being supercoiled by the
bugs (DH5alpha).  I have tried LB and TB, and both CsCl preps and Wizard
preps are giving the same result.  I also re-transformed the bugs with
older supercoiled preps, and subsequently they are no longer supercoiled. 
Any help would be appreciated.

Please respond to boehnin1 at

Darren Boehning
Dept. Pathology and Cell Biology
Thomas Jefferson University

More information about the Methods mailing list