X-Message-Number: 22038
From: 
Date: Sat, 21 Jun 2003 04:19:05 EDT
Subject: Re: Copal, cheap long-term preservation protocols

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Re: Copal, cheap long-term preservation protocols
From: "D. den Otter" <>
> 
> Well, that aside, the relatively low cost of such procedures would
> significantly lower the preservation threshold, which can only be a good
> thing IMO. Anyway, do you think copal encasement would be superior to
> storage in a polyester resin, such as the one used for Plastamounts (see
> http://www.carolina.com/general/departments/mounting_services.asp , scroll
> down)? The latter is widely used and should thus be much easier and
> cheaper to obtain [than copal].

I don't think copal is superior, simply it mimics what was done by ancie, 

chineses at their best four or five millenia ago. So we know how it works in the
long run with poor environment. In the very long run, copal turns to amber, a 
product able to stay here for millions of years.

Copal is a simple technology: grind it, disolve it in some organic solvent, 
inject and let dry. I use acetone because it seems to be ready to penetrate 
biological samples and then evaporate fast. What it does at molecular level or 
even cell structural level would needs some instruments to be looked for.

The copal tech. is a last chance process, it could be keep in store by 

cryonics organizations for use in case of emergency: Major social disruption 
with no 
more LN2 on the market, bad law asking for burial for example.

Your plastination is more evolved and more costly. I agree that it would have 
to be tested, unfortunately I have not the money at the time, may be next 
year.

There is a personnal story: When I was a young boy I made some plastic copies 
of lenses, the idea was to get the general shape and then to polish it as if 
it where a glass element. Unfortunately, the large entangled polymerized 

molecules don't allow a good polishing, so I let that project. Many years later,
I 
found again these samples, the clear plastic had turned brown. The surface was 
sticky, so the product displayed some decomposition/oxidation effects. I 

wouldn't not bet on it for centuries. I think you could argue that with the 
right 
product such thing don't happen, but the right product is a carefuly made mix, 
you can't know what it will give when mixed with thousandts of biological 
molecules of all kinds.

Another problem: The polyesther I have seen are quite sticky, copal with 
acetone looks as brown water.

Yvan Bozzonetti.


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