Greehey CCRI Histology

Histotechnology is the science devoted to the microscopic detection of tissue abnormalities and antigens associated with disease or other cellular mechanisms. By applying specific reagents, chemicals, and dyes, tumor specimens are prepared for microscopic evaluation. A histotechnician’s expertise lies in combining knowledge of chemical reactions with an understanding of tissue composition, enabling precise staining techniques that differentiate between distinct tissue and cellular structures. These differences in appearance under the microscope allow for the detailed analysis of protein–antigen interactions.

In a histology laboratory, the process of obtaining results typically involves five key steps:

1. Grossing and Fixation

During grossing, specimens obtained from scientific investigations are carefully examined, described, and trimmed to the appropriate size. They are then placed into pre-labeled tissue cassettes containing unique identifiers. To preserve the integrity of the sample, the specimens are immersed in a fixative solution—such as formalin or paraformaldehyde—which prevents decomposition. This critical preservation step is known as fixation.

2. Processing

Tissue samples are processed using a Leica ASP300S automated vacuum tissue processor, which removes residual aqueous solution and gradually infiltrates the tissue with paraffin wax. The paraffin infiltration provides structural support, enabling the tissue to be cut into ultra-thin slices suitable for microscopic examination.

3. Embedding

Following processing, the tissue is transferred to the Leica EG1160 Tissue Embedding Station, where cassette tissue samples are embedded in paraffin blocks of appropriate size to provide additional support for sectioning. Once embedded, the tissue blocks are placed on a cold plate to solidify before proceeding to microtomy, the process of cutting the tissue into thin sections.

4. Sectioning

The tissue block is secured onto an Olympus CUT 4060 microtome, where a slicing knife attachment trims sections of tissue, typically ranging from 3 to 5 micrometers in thickness. As the tissue is cut, consecutive sections form a ribbon, which is gently floated on warm water to soften and flatten the tissue. Individual sections are then transferred onto properly labeled microscopic slides and stored for subsequent procedures.

5. Staining

Staining enhances tissue visualization by causing components to take on distinct colors when exposed to specific dyes and reagents. In addition to traditional dyes, antibodies may be applied to detect targeted antigens through a method known as immunohistochemistry (IHC). Once staining is complete, the prepared tissue sections are ready for microscopic examination by a scientific investigator.

Technical Services

• Immunohistochemistry Staining (research antibodies) (Dako AutostainerLink48)
• Frozen Sections (Leica CM1520)
• Histochemical Staining
• Tissue Processing
• Paraffin Embedding
• Microtomy Unstained Tissue Sections
• Tissue Microarray (TMA)
• Hematoxylin & Eosin (H&E stain)
• Comprehensive tissue sample processing from start to finish
• Custom tissue microarray construction
• Routine and special staining, immunohistochemistry (IHC) on tissue samples and cellular pellets
• Extensive in-house antibody library for IHC (see our test menu)
• Optimization and validation of new IHC antibodies
• Board-certified histotechnician dedicated to overseeing project processing and staining
• Rapid turnaround times with uncompromising quality

Please note that if you are seeking services not listed, don’t hesitate to get in touch with us.

HISTOLOGY LABORATORY REQUISITION FORM