Chemical Fixation
Chemical Fixation - Related Videos
07:54
Preparing Adherent Cells for X-ray Fluorescence Imaging by Chemical Fixation
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Cited by 14 •
2015
Here, we present a protocol on how to determine the quantity and distribution of metals in a sample using synchrotron X-ray fluorescence. We focus on adherent cells, and describe the chemical fixation method to prepare this sample. We then describe how to mount and image the sample using synchrotron X-rays.
04:19
Pressure Fixation of Isolated Murine Pulmonary Valve: A Procedure to Isolate and Chemically Fix the Mouse Pulmonary Valve in Closed Conformation
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2025
In this video, we describe the procedure to isolate and chemically fix the mouse pulmonary value in closed conformation via perfusion pressurization.
14:38
Establishment of Microbial Eukaryotic Enrichment Cultures from a Chemically Stratified Antarctic Lake and Assessment of Carbon Fixation Potential
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Cited by 5 •
2012
Microbial eukaryotes are both a source of photosynthetically-derived carbon and top predatory species in permanently ice-covered Antarctic lakes. This report describes an enrichment culture approach to isolate metabolically versatile microbial eukaryotes from the Antarctic lake, Lake Bonney, and assesses inorganic carbon fixation potential using a radioisotope assay for Ribulose-1,5-bisphophate carboxylase oxygenase (RubisCO) activity.
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.
FAQs
Aldehyde and alcohol fixatives stabilize specimens through different chemical effects. Aldehydes form cross-links between proteins, helping retain cellular architecture. Alcohol-based agents remove water and precipitate cellular components, which also slows enzymatic degradation and decomposition. This mechanistic distinction explains why fixative selection can produce different preservation outcomes in the same biological material.
Preservation quality and antigen accessibility can change with fixative choice and exposure conditions. Aldehyde cross-linking may stabilize structure effectively, but chemical modification can influence whether biomolecules remain accessible for immunostaining. Alcohol-based agents act differently by removing water and precipitating components. Consequently, the best fixation strategy depends on whether structural retention or downstream molecular detection is the priority.
By slowing enzymatic degradation and decomposition, fixation preserves material long enough for biological structures to be examined rather than rapidly altered. This is especially important when researchers need to compare tissue architecture or cell morphology across specimens. Stabilization therefore supports observation of structural differences that might otherwise be obscured.
Exposure conditions influence how thoroughly a specimen is stabilized and how well its structures remain suitable for later analysis. Inadequate or mismatched conditions may compromise preservation quality, while conditions that alter chemical accessibility can affect immunostaining. For this reason, fixation should be considered together with the intended observation method and the biomolecules that must remain detectable.
An effective workflow begins by matching the fixative to the biological specimen and the planned analysis, then controlling exposure conditions before microscopy, histology, or immunostaining. The key decision is not simply to preserve visible shape: researchers must also consider whether fixation will maintain access to relevant biomolecules. This coordination improves the interpretability of downstream observations.
In biology, the method supports microscopy and histology by retaining tissue architecture and cell morphology, while immunostaining depends on whether target biomolecules remain accessible after treatment. These uses connect structural preservation with molecular localization. It is therefore valuable for examining disease-related structural changes, provided the fixation strategy matches the analysis and its interpretive requirements.