X-Message-Number: 29479
From: "Basie" <>
Subject: Ethanol prevents freeze damage
Date: Tue, 1 May 2007 17:15:44 -0400

Ethanol prevents freeze damage



Freezing without Ice Crystal Damage: Semithin and Ultrathin Frozen Sections 
of Ethanol-Infiltrated Tissue for Microscopy, with Applications to 
Immunocytochemistry
Authors:
 Christensen, A. Kent; Lowry, Terry B.
Publication:
 Microscopy and Microanalysis, vol. 01, Issue 05, p.217-230
Publication Date:
 10/1995
Origin:
 CUP
Keywords:
 frozen sections; ultrathin frozen sections; ethanol (ethyl alcohol); light 
microscopy; electron microscopy; sectioning; immunocytochemistry; liver; 
pancreas; rat.
Bibliographic Code:
 1995MiMic...1..217C

Abstract
Ethanol (ethyl alcohol) has long been a standard reagent used in preparing 
tissues for light and electron microscopy. After fixation, tissues are 
usually dehydrated with ethanol before being embedded in paraffin or 
plastic. In this study we show that the ethanol-infiltrated tissue can be 
frozen and sectioned directly without embedding. When tissue impregnated 
with ethanol is cooled below about [minus sign]117 C with liquid nitrogen, 
the ethanol solidifies without appreciable crystallization. The frozen 
tissue can then be sectioned in a commercial cryoultramicrotome that is set 
at [minus sign]155 to [minus sign]170 C to produce semithin frozen sections 
(0.5 to 3 [mu]m thick) for light microscopy or ultrathin frozen sections (50 
to 100 nm thick) for electron microscopy. Sections are picked up and mounted 
on glass slides or EM grids by means that are in current use for ice 
ultrathin frozen sectioning. Because there is no apparent freezing damage, 
the morphology in these ethanol frozen sections of unembedded tissue appears 
generally quite good, often resembling that obtained by conventional EM 
techniques. Examples are provided that illustrate the use of this material 
for immunocytochemistry at the light and electron microscope levels. 

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