thank you Patricia!  i have learned so much from everyone oin this group.  when 
would i have a chance to talk with scientists working with this sort of thing.  
only wish i could go back to school for the rest of my life andlearn everything 
that i want to know.  so once again, thanks for teaching me something new.  
---- wrote: 
> Interferon is a protein.  It is dried into a powder which should be able 
> to be frozen with
> no problem.  But when proteins are dissolved into a liquid solution, 
> freezing can be tricky.
> As a scientist working with a variety of proteins, I can tell you that 
> many proteins will start
> to break down if frozen more than once.  And rapid freezing is preferable 
> to slow freezing.
> At home, the closest thing to rapid freezing could be done by putting the 
> protein tube into ice in the back of
> the freezer lowering
> the temp more rapidly than if you just stick it on the shelf in the 
> freezer.  Proteins also generally
> survive freezing better if they are more dilute and freezing in smaller 
> portions will allow the
> freezing to go faster than freezing in big portions.
> If a protein is degraded by freezing, it's structure starts to unwind. 
> Some molecules of the
> protein in the solution may degrade and others won't so you may still see 
> that the protein has
> some activity or it may lose all activity.  You might see some precipitate 
> in the solution (always
> a bad sign) or you might not.  Without some kind of activity readout, it 
> seems impossible
> to me to know whether freezing is causing a problem.
> In summary, I would make up the solution to the appropriate dilution and 
> freeze it in the smallest
> portions that will work (need appropriate sized containers) in the coldest 
> part of the freezer in ice.
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