Rearranging Plasmid

[Shin-ichiro HIRAGA]

Sometimes, plasmids rearrangement (truncation?) occur even in recA- 
strains, particularly on high-copy plasmids such as pUC.

One strategy to avoid such rearrangement is propagate the culture at 
lower temperature (ex. 30 degree). Since the copy number regulation of 
pUC or related plasmids is temperature-sensitive, copy number of these 
plasmids are low at lower temp. 
Sometimes this strategy works well (sometimes, not). 

I believe it'is easy to try.