X-Message-Number: 12000 Date: Thu, 24 Jun 1999 20:40:29 -0700 (PDT) From: Doug Skrecky <> Subject: stability of freeze-dried tissue Authors Takahashi R. Matsuo S. Okuyama T. Sugiyama T. Institution Department of Pathology, Faculty of Medicine, Kyoto University, Japan. Title Degradation of macromolecules during preservation of lyophilized pathological tissues. Source Pathology, Research & Practice. 191(5):420-6, 1995 Jun. Abstract 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