X-Message-Number: 12000
Date: Thu, 24 Jun 1999 20:40:29 -0700 (PDT)
From: Doug Skrecky <>
Subject: stability of freeze-dried tissue

  Takahashi R.  Matsuo S.  Okuyama T.  Sugiyama T.
  Department of Pathology, Faculty of Medicine, Kyoto University, Japan.
  Degradation of macromolecules during
  preservation of lyophilized pathological tissues.
  Pathology, Research & Practice.  191(5):420-6, 1995 Jun.
  Methods of preserving biological specimens are becoming more important due to
  recent advances in molecular biological analysis. Storing samples in a
  freezer, however, is still the most commonly used method of preserving
  pathological specimens. We investigated the feasibility of using freeze-dried
  tissues stored at room temperature as an alternative method of preserving
  tissue samples for molecular analysis at the DNA, RNA, and protein levels.
  The freeze-dried tissues were transferred to a sealed vial filled with
  nitrogen gas and kept for months at room temperature. DNA and protein were
  stably preserved for at least 24 weeks. RNA, however, showed slight
  degradation after 10 weeks of storage. Controlling moisture
  and temperature during long-term storage was found to be important, as it
  significantly affected the stability of these cellular molecules in tissues.
  Shelf-stable preservation eliminates the need for storage in a freezer and
  allows convenient shipping of samples to distant places. These findings
  should provide practical basis for the development of a convenient and
  economical way of preserving pathological specimens for a variety of analyses
  in the field of molecular biology.

  Additional note by poster:

     This illustrates once again that the only acceptible form of
  long-term storage of tissue, is as a glass. Deterioration is too rapid
  above Tg' termperatures, whether this be dry ice storage of glycerol
  treated frozen tissue, or storing freeze-dried tissue with a high
  residual moisture content at room temperature. 

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12000