Histology

Products for Your Workflow

Histology is the study of the microscopic anatomy of cells and tissues. Fisher Scientific offers a wide range of chemicals and reagents, including histology-grade solvents, designed specifically for medical laboratory professionals. Let Fisher Scientific help you find everything you need for use in your histology applications. Explore products by technical procedure:

Sample Preparation
Embedding and Sectionning
Staining and Imaging
Storage

Shop by PCR and qPCR Methods

Sample Preparation

In the fixation stage, a fixative is used to modify tissue by stabilizing the protein, so it is resistant to further changes; thus, fixatives are used to protect tissue from degradation and to maintain the structure of the cells, including sub-cellular components, such as cell organelles (nucleus, endoplasmic reticulum and mitochondria). In the processing stage, tissues must go through a dehydration process to replace water with the material that will be used for embedding, so the tissue samples adhere to the embedding material. The most common technique is paraffin wax embedding.

Samples are immersed in multiple baths of progressively more concentrated ethanol to remove water from the tissues, followed by a clearing agent, such as xylene, to remove the alcohol and finally hot molten paraffin wax, which replaces the xylene and infiltrates the tissue.

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Dissection Equipment

Special Purpose Benchtop Centrifuges

Tissue Dehydrants

Embedding and Sectionning

In the embedding process, tissue samples and liquid embedding material are placed into molds and allowed to harden. The hardened blocks containing the tissue samples are then ready to be sectioned. Embedding can also be accomplished using frozen, non-fixed tissue in a water-based medium, usually a water-based glycol or resin.

In the sectioning phase, the tissue is sliced into very thin (0.5 - 10 microns; 1000 microns = 1mm) sections using a microtome. These slices, usually thinner than the average cell, are then placed on a glass slide for staining. Frozen tissue embedded in a freezing medium is cut on a microtome in a cryostat.

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Embedding Cassettes and Storage

Cryostats and Accessories

Microtomes and Accessories

Staining and Imaging

Routine staining is done to give contrast to the tissue being examined. Hematoxylin and Eosin (H&E) are the most commonly used stains in histology.

Hematoxylin is combined with a metal mordant, such as aluminum, and the hematoxylin-aluminum complex is used to stain cell nuclei blue/black. Eosin is the most widely used counterstain in the routine staining of tissue sections. The best staining with eosin occurs at pH 4.5 to 5, and when used properly, at least three shades of pink can be obtained. Erythrocytes, collagen and the cytoplasm of epithelial or muscle cells should stain different shades of pink when using eosin. Samples are immersed in multiple baths of progressively more concentrated ethanol to remove water from the tissues, followed by a clearing agent, such as xylene, to remove the alcohol and finally hot molten paraffin wax, which replaces the xylene and infiltrates the tissue.