X-Message-Number: 7448
From:  (RL)
Newsgroups: sci.cryonics
Subject: freezing  suggestions
Date: Tue, 07 Jan 1997 11:24:14 GMT
Message-ID: <>

I used to do lab research on cell membranes a few years ago. 

One method we used was to create a surface replica of the membrane and
examine it under electron microscopy. To do this, we obviously needed
to work with intact, non-ruptured cells. 

We found that placing tissue directly in liquid nitrogen didn't work
because the LN has too low a thermal density, and doesn't therefore
remove the heat fast enough, allowing the water in the cells to
crystalize and cause damage. 

Instead, we first placed the tissue in liquid freon and allowed it to
cool that way. The freon is higher temperature but also much higher
thermal density and cooled the tissue quickly enough to avoid
crystalization. We then placed the tissue in liquid nitrogen for final
cooling.

My suggestion is the following procedure:

1) Replace blood with synthetics which do not crystalize as easily

2) Lower the body temperature to near freezing

3) Cut open the body and most particularly the skull, to allow maximum

penetration of the coolant. At this stage organs may need to be
exposed and freed from their surrounding connective tissue to allow
maximum coolant contact.

4) Immerse the body in liquid freon until frozen. At this stage it may
be necessary to provide tubes and channels to make sure the coolant
penetrates all body cavities quickly. The lungs, in particular, and
the brain may require special preparation and cooling.

5) Transfer to liquid nitrogen.

Has this been tried? Any comments?

RL



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