"Orange" pellet in plasmid mini-prep

Ray Boykiw rhboykiw at acs.ucalgary.ca
Wed Jun 10 17:03:17 EST 1998


We are having an interesting problem with a very simple and standard
technique.  At the moment, when we do DNA plasmid minipreps (pCRScript
in XL-1B) from LB broth cultures +AMP, we are getting no plasmid. The
growth appears normal in the broth, and also on LB+AMP plates.   We
have tried different miniprep methods, new reagents, etc. etc., but
nothing seems to work.  One thing that appears slightly different is
that when we pellet the bacteria from the broth culture, the pellet
appears slightly orange compared to what we are used to.  This is the
only noticeable change from our normally problem-free techniques.  Not
only have we noticed this problem, but other labs not related to ours
are also currently having this problem, and noticing slightly orange

 Has anybody else ever seen this before?

What caused it?

(Most important) Is there a solution to this problem?

Thank-you for your time.

Ray Boykiw
University of Calgary
Faculty of Medicine

More information about the Methods mailing list