X-Message-Number: 10404
Date: Wed, 9 Sep 1998 12:44:58 -0700 (PDT)
From: Doug Skrecky <>
Subject: formalin versus methanol

  Noguchi M.  Furuya S.  Takeuchi T.  Hirohashi S.
  Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
  Modified formalin and methanol fixation methods for
  molecular biological and morphological analyses.
  Pathology International.  47(10):685-91, 1997 Oct.
  Several simplified fixation methods were examined to
  determine their suitability for both molecular biological analyses and
  morphological study. Fixation with 10% v/v formalin alone at
  4 degrees C and containing 5 mmol/L ethylenediamine-N,N,N',N'-tetraacetic
  acid (EDTA) at room temperature preserved significantly more
  high-molecular-weight DNA than 10% v/v formalin fixation at
  room temperature. The morphological differences between
  tissues fixed using these modified formalin
  fixation methods and conventional 10% v/v formalin
  fixation were negligible. Of the dehydration fixatives
  tested, 100% methanol did not cause regional differences due to artificial
  tissue shrinkage and the morphology of sections prepared by
  methanol fixation was preserved consistently better than
  that of acetone- or ethanol-fixed sections. All three dehydration fixatives
  preserved relatively higher-molecular-weight DNA and RNA, compared with
  formalin. Cold formalin, formalin containing EDTA at room temperature and
  100% methanol are recommended as standard and additional fixatives routine
  clinicopathological laboratory use.

  Additional note by poster:

    IMHO the improved preservation with formalin or methanol versus
  acetone or ethanol, probably relates to the higher permeability of the
  former fixatives into quickly autolyzing tissues. This also serves to
  emphasize the need for prompt treatment of patients for cryonics or any
  indeed preservation protocol.

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