E. coli preservation

[Rafael Maldonado]

Chris Fields wrote:
> 
> My professor has several strains of E. coli and Salmonella in stab
> cultures that are still viable after 20 years!  I think that you have to
> be VERY careful with the phenotype.  A few of his were DOA due to
> thymineless death (had a thyA mutation).  I guess his grad student at
> the time had left out the thymidine; my prof was a bit pissed.

PLasmids can be lost vith variable frequency in stab, even F primes...

-- 
Rafael Maldonado, Ph.D.
Division of Genetics
University of Alicante (Spain)