Histology Articles
Non-Aldehyde Fixatives
Mercury Based Fixatives Mercurials contain mercuric chloride. Their method of tissue fixation is poorly understood. While not penetrating tissue well and causing some tissue hardness, mercurials are fast and provide excellent nuclear detail. They are commonly used to fix hematopoietic and reticuloendothelial tissues. Alcohol Fixatives Alcohols, including methyl alcohol (methanol) and ethyl alcohol (ethanol), are…
Read MoreImmunohistochemistry
Immunohistochemistry is the application of antibody/antigen interactions to provide information about biological systems. The body’s response to the introduction of a foreign agent, known as the immune response, results in the production of antibodies which bind the offending material. Antibodies bind tightly and specifically to an “epitope” (one specific structure) on an “antigen” (foreign molecule…
Read MoreAldehyde Fixatives
Formaldehyde and glutaraldehyde are the most commonly used aldehyde fixatives. They work by forming cross-links both within and between proteins, particularly between lysine residues. Damage to the tertiary structure of the proteins occurs on a limited basis. Formalin (37% aqueous formaldehyde) is normally diluted 10 fold and neutrally buffered to make a working fixative solution…
Read MoreOverview of Fixation
To maintain the tissue in as lifelike a state as possible, tissue for analysis is usually placed directly into a fixative solution upon removal from the body. Fixation is normally carried out as soon as possible to prevent autolysis and to reduce possible infectivity. Several factors determine the choice of fixative for a given application.…
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