X-Message-Number: 4768
Date: Sat, 12 Aug 1995 03:18:39 -0700 (PDT)
From: Doug Skrecky <>
Subject: Cryonics & Fixation

    In message #4750 Mike Darwin mentioned that aldehyde fixatives do not
fix lipids. This is not entirely true. Analysis of brains fixed in
formaldehyde for 24 years indicates that cholesterol, cerebrosides,
sulphatides, sphinogomyelin and phosphoinositides are very well preserved.
(Journal of Histochemistry and Cytochemistry Vol.10 704-709 1962)
    The problems Mike notes regarding perfusion with aldehydes could be
avoided by switching to an alcohol based fixative. Kryofix (Merck, product
no. 5211) might be a preferred alternative since it consists of the
cryoprotectant and fixative ethyl alcohol and the cryoprotectant
polyethylene glycol. (Path Res.  Pract. Vol.188 832-835 1992)
    Mike also notes that formaldehyde does not prevent mold growth. An
analysis of 18 medical schools in the UK has found that mold growth did
not occur when the embalming fluid contained less than 25% tap water. One
such fluid had a composition of 625 ml/l of industrial metholated spirit,
207 ml/l glycerol, 53 ml/l formaldehyde, 48 ml/l distilled water and 67
g/l phenol. (Journal of Anatomy Vol.182 295-297 1993)

    Sincerely Doug Skrecky


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