Plasmid Storage

Michael Benedik bchs1b at Elroy.UH.EDU
Thu May 13 12:37:41 EST 1993

In article <wra-130593115239 at>, wra at (Bill Abrams) writes:
>We are trying to decide on the best long-term storage method for plasmid
>clones. We have found glycerol stocks to be stable for only 1-2 years,
>especially when stored at -20 deg C instead of -70 deg C. One suggestion is
>to store 1-2 ug plasmid DNA in 70% ethanol at -20 deg C. If clone is then
>required dry down in SpeedVac, and transfect. Alternative techniques 
>or suggestions would be appreciated. If desired, I will post the results of
>this query. Thanks!
>Bill Abrams
>wra at

Bacterial strains need to be at -70 for long term storage. Then they
are good for years/decades. Plasmid DNA can easily be stored as DNA
in TE just at 4oC, or in 70% ETOH, or as a dried pellet. I have stocks
of plasmid in TE at 4oC which are nearly 10 years old and they still
cut, transform, ligate well etc. The only concern is to not get them
contaminated, so just make a master tube only for archival purposes that
you go into very seldom, and store this cold/frozen.

 Michael Benedik				INTERNET: Benedik at
 Dept. of Biochemical & Biophysical Sciences	
 University of Houston				BITNET: Benedik at uhou

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