Cloning Unstable Sequences

[Edgar Valencia]

Hi Jon:
> Does anyone have any suggestions regarding the following parameters.
> 
> 1)  Bacterial strain and growth conditions. Has anyone found that some
> strains and/or conditions work much better than others. 

Try recA minus strains to avoid recombination we use sometimes DH5 apha 
or HB101 and they work fine for us at least. There are other strains that 
are better than this if you can get them

> 2)  Vector.  Are unstable inserts more stable in some vectors than others,
> particularly with regard to copy number.

Try a low copy-number vector. There are several reports dealing with 
unstability due to active replication plus a secondary structure

Some derivatives of RSF1010?

I hope this helps

Edgar
CIFN-UNAM
Mexico