Frozen restriction enzymes

[Richard P. Grant <MDE>]

Most restriction enzymes come frozen solid on dry ice.  We routinely store
our backup stocks at -80 with no worries.  BUT, we never freeze back down
to -80 once they've warmed to -20.

Richard

Michael Sachsamanoglou (michaels at PHARM.MED.YALE.EDU) rearranged the electrons to say:
: Hi Netters,

: Here is my quick question:
: What happens when a restriction endonuclease solution is frozen to -80C?
: Is it normal for the 50% glycerol storage solution to solidify at this 
: temperature? I've heard sometime ago that if a restriction enzyme 
: freezes it is dead. Is this true? Thanks for any answers.

: Mike