pLysS freezer stock instability
edbeaty at uxa.cso.uiuc.edu
Tue Mar 21 18:13:25 EST 1995
> In article <3k1qej$4ia at service1.uky.edu>, Frank van de Loo
<fvandelo at ca.uky.edu> writes:
> > Dear methodists,
> > I find that my BL21(DE3)pLysS competent cells, and pET-containing
> > strains derived from them, lose their chloramphenicol resistance
> > during storage at -80.
Pardon me if this was in the original article, but I missed the first time
around. Were you able to recover pLysS from the cells after regrowing
them? I know that the lysozyme can cause strains with pLysS to lyse when
they get near freezing...maybe most of your plasmid-carrying cells are
lysing when you start to freeze them? One time I was trying to prepare
electrocompetent BL21(DE3)pLysS I centrifuged my cells in a cold (4 C)
rotor...I ended up with a very gooey pellet.
Just a thought,
Department of Microbiology
University of Illinois-Urbana
Ed_Beaty at qms1.life.uiuc.edu
"A mime is a wonderful thing to waste."
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