Fragility of plasmids: size limit for shaking/vortexing?

[Kevin A. Mulcahy]

Hi,

following restriction digestions with heat-resistant restriction enzymes 
and CIAP, I have to phenol:chloroform extract the samples in order to 
remove the enzymes. Some of my fragments are only 1.5 kb and seem to 
tolerate quite vigorous shaking by hand (necessary to for efficient 
extraction by phenol:chloroform). However, one of my plasmids is 10.5 
kb. Does anyone know if plasmids (pre-linearised) which are this large 
can be shaken vigorously without causing cleavage of the linear DNA 
fragment? If not, then what is the best way to extract them with 
phenol:chloroform?

Many thanks,

Kevin Mulcahy.