Cryo-fixation
Cryo-fixation - Related Videos
10:21
Protocol for HER2 FISH Using a Non-cross-linking, Formalin-free Tissue Fixative to Combine Advantages of Cryo-preservation and Formalin Fixation
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Cited by 3 •
2017
Fluorescence in-situ hybridization (FISH) is often required in combination with histopathology and molecular diagnostics for selection of therapy in personalized medicine. A novel non-cross-linking, formalin-free tissue fixative that allows high quality morphologic, molecular and FISH analyses from the same specimen by addition of a post-fixation step before FISH is presented.
08:53
Whole Animal Perfusion Fixation for Rodents
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Cited by 531 •
2012
Here we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain.
05:05
Preparation of High-Temperature Sample Grids for Cryo-EM
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Cited by 5 •
2021
This paper provides a detailed protocol for preparing sample grids at temperatures as high as 70 °C, prior to plunge freezing for cryo-EM experiments.
01:03
Fixation and Sectioning
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2023
Two basic types of preparation are used to visualize specimens with a light microscope: wet mounts and fixed specimens. The simplest type of preparation is the wet mount, in which the specimen is placed in a drop of liquid on the slide. A liquid specimen can be directly deposited on the slide using a dropper. Solid specimens, such as skin scraping, can be placed on the slide before adding a drop of liquid to prepare the wet mount. Sometimes the liquid is simply water, but stains are often added...
09:59
Preparation of Primary Neurons for Visualizing Neurites in a Frozen-hydrated State Using Cryo-Electron Tomography
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Cited by 24 •
2014
To preserve neuronal processes for ultrastructural analysis, we describe a protocol for plating of primary neurons on electron microscopy grids followed by flash freezing, yielding samples suspended in a layer of vitreous ice. These samples can be examined with a cryo-electron microscope to visualize structures at the nanometer scale.
FAQs
Rapid cooling is essential because it immobilizes water and cellular components before they can rearrange. If freezing is too slow, ice crystals can form and disrupt membranes, organelles, and macromolecular assemblies. By limiting those physical changes, cryo-fixation gives imaging methods structural evidence that more closely reflects the specimen’s original organization.
High-pressure freezing and plunge freezing are the two freezing routes identified for cryo-fixation. Both are selected to cool a specimen rapidly enough to avoid ice-crystal formation, but the overview does not assign them identical performance or specimen limits. Their shared purpose is to preserve cellular architecture for subsequent structural imaging.
Maintaining membranes, organelles, and macromolecular assemblies in near-native organization matters because observed spatial relationships can be interpreted as biological structure rather than changes introduced during preservation. This is particularly important when a study examines complex cell architecture or molecular organization, where small distortions could alter conclusions about how components are arranged.
Once a specimen has been cryo-fixed, the preserved material can be examined by electron microscopy, cryo-electron tomography, or correlated imaging. These approaches provide structural evidence from the same preserved state, allowing investigators to study membranes, organelles, and macromolecular assemblies with minimal artifact in biological specimens.
Biologists can apply cryo-fixation to studies of cell architecture, infection, development, and dynamic biological processes. Its value across these areas comes from capturing organization before chemical or physical changes obscure it. The resulting structural evidence can help investigators examine how membranes, organelles, and macromolecular assemblies are arranged in the biological context under study.
Correlated imaging benefits from cryo-fixation because the specimen’s preserved structural state can be used alongside complementary imaging observations. This makes the method useful when researchers need to relate cellular architecture to molecular organization rather than examine either level alone. It therefore supports integrated analysis of biological structure.