RE: freezing whole animals

From:Jim at ProSciTech <>

I expect that freezing the corpse in a conventional freezer would do for your 
purposes. This is assuming that you do not want to greatly enlarge the 
negative. Ice crystal-free freezing is only possible with tiny specimens. So 
arguably the entire cryogenics industry, which is preserving human bodies in 
liq nitrogen for subsequent revival (who on earth needs that) is nonsense. If a 
whole mouse body is frozen most cells will be ruptured by large ice crystals. 
Freezing has to be around 100 degrees in milliseconds, which is patently not 
possible within large specimens. Its not the thawing that does the damage, but 
it's then that it becomes obvious.
Limited success in freezing largish specimen has been achieved with rather dry 
specimen (low water contents limits freezing damage; dry grain can be frozen in 
a freezer and remain viable). It's also possible to perfuse with anti-freeze. 
The effect of that is that ice may only form when, say -30C is reached and 
after -100C no damage occurs. So the freezing time is shortened. Some 
amphibians use there own anti-freeze, clever things!
Jim Darley
ProSciTech                 Microscopy PLUS
PO Box 111, Thuringowa  QLD  4817  Australia
Ph +61 7 4774 0370  Fax:+61 7 4789 2313
Great microscopy catalogue, 500 Links, MSDS, User Notes
ABN: 99 724 136 560            

On Thursday, October 05, 2000 12:56 AM, 
[] wrote:
> All the discussion on freezing and artifacts has been very interesting.  I
> was wondering if anyone has used that liquid nitrogen "slush" method to
> freeze a whole rat or mouse for whole body autoradiography?
> Thanks
> Gina Sennello
> Gilead Sciences Inc.
> Boulder, CO

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