About Histotechnology

What is Histotechnology?

Histotechnology is a science centering on the microscopic detection of tissue abnormalities for disease diagnosis and the treatment of diseases. Utilizing specific reagents, chemicals, and dyes, the Histotechnologist prepares surgical specimens for microscopic screening by the surgical pathologist. This knowledge of chemical reactions, combined with an understanding of tissue composition, allows the Histotechnologist to stain the tissue in a way that distinguishes distinct tissue and cellular structures. The difference in appearance of these tissue cells under a microscope allows a pathologist to ultimately render a clinical diagnosis and guides treatment options for the patient.

In the modern histology lab, immunohistochemistry (IHC), digital pathology, and molecular (DNA/RNA) techniques are frequently utilized to provide accurate tumor identification which will aid the clinician in selecting a treatment strategy that offers that greatest probability of cure.

Histotechnologist Skills

Tasks performed by the histotechnologist require patience, mechanical ability, knowledge of biology, immunology, molecular biology, anatomy and chemistry. Histotechnology requires five basic steps, each an integral part of the histotechnologist‘s job:

Grossing and Fixation

Grossing & Fixation

Tissue specimens taken from routine surgical cases, autopsies, or other scientific investigations are examined, described and trimmed to proper size. This process is referred to as “grossing the specimen”. The resulting specimens are preserved by placing them in solutions designed to prevent decomposition. This is known as fixation.

Embedding

Embedding

Before the wax permeated tissue can be cut it is placed in a larger wax block for additional holding support during sectioning.

Processing

Processing

Water is removed from the tissue and replaced by melted paraffin wax. The wax infiltrates the tissue and provides the necessary support when cutting the tissue into thin slices which will eventually be examined under a microscope.

Sectioning

Sectioning

The tissue is mounted onto a delicate instrument called a microtome. An extremely sharp knife is used to cut sections of the tissue embedded in the wax block. These sections are cut one after another to form a ribbon, which is floated on warm water to soften and flatten tissue sections. These sections are then placed on microscopic slides and stored for future procedures.

 

Staining

Staining 

Staining causes tissue components to change colors when brought into contact with different chemicals. In addition to dyes, antibodies are reacted with tissues to identify specific tumor cell lines with a method called Immunohistochemistry. This technique is critical to guiding the patient’s physician in selecting the most effective tumor treatment. DNA probes are also applied to tissue sections to identify the presence of bacterial and viral infections and some tumors. When staining is completed, the tissue section is ready for examination under a microscope by a pathologist or other scientific investigator. Without specialized staining techniques, many tissue components would remain invisible.