Help about methylation and SexAI

[Frank O. Fackelmayer]

Gianluca Molla wrote:
> 
> Hi everyone,
> I need to use the SexAI restriction enzyme. On the NEB catalog
> is stated that this enzyme DO NOT cuts if its reconition
> site is methylated by dcm methylase.Now I think I have
> to purify my DNA from a E.coli strain that is dcm-, 

yes, you´re right.

> but
> almost every cloning strain in cdm+ (except JM110).
> Can I use this strain or its genotype is not good for cloning
> and plasmid amplification? 

JM110 is ok for plasmid amplification. However, this strain is
notoriously bad for transformations. So, don´t use JM110 for standard
cloning, e.g. for transformation with ligation products. 


Hope this helps,
Frank