Maxipep "problem"

Mark Thornton mthorn at
Thu Dec 29 10:00:32 EST 1994

> Maxiprep problem?
> The last weeks we have observed some weird bands in our maxipreps.
> If we apply some of our maxipreps without restiction on a agarose gel a 
> faint band of about 1 kb is seen. It is really a band and not a RNA 
> smear. Restriction
> of the vector removes the band. The maxipreps were grown fresh from a 
> single
> colony.
> Is it possible that the bacterial host strain is contaminated with 
> something?
> Any suggestions are very welcome.
> Thanks, 
> Jurgen Seppen
> Academic Medical Center
> Amsterdam
> The Netherlands

We sometimes get a 700bp-1kb band in our maxi preps- we came to the 
conclusion it is an F'plasmid which the majority of host cells contain. 
It may be this plasmid in your case as well .  Unfortunately we haven't 
found a simple way of getting rid of it so far.  Any suggestions would be 
gratefully received.

Angela Daffada
Institute of Cancer Research, LONDON UK

Replies to angela at

More information about the Methods mailing list