best method to lyse bacteria for recombinant protein purification

[Tim Chipman]

: Another technique which we have used but to which we have limited access
: is French Press.  This basically forces your sample through an
: incredibly tiny aperture, shearing your cells open.  The nice thing
: about this is that you can run your sample through many times and, if it
: is at 4C, not worry about unnecessary heating.

Just as a friendly comment, the lysis induced by french pressure cells is
not due to the aperture size, but rather the rapid transition from (say) 
15,000 PSI to atmospheric pressure.

-Tim