Routine Histology Services

The routine histology services offered by the Breast Center pathology laboratory are as follows:

• Fixation
• Paraffin Processing and Embedding
• Frozen Embedding
• Microtomy
• Hematoxylin and Eosin Staining (H&E)
• Special Histochemistry

The primary goal of fixation is to arrest the autolysis and putrefaction of tissues with the goal of stabilizing the morphological structure and biochemical relationships between constituent proteins for subsequent analysis (e.g. H&E, immunohistochemistry, etc.). Fixation for paraffin processing is typically performed using commercial grade 10 percent Neutral Buffered Formalin.

Paraffin processing involves three major steps; dehydration using ethanol, clearing with xylenes, and infiltration with paraffin. We use state of the art Sakura Tissue-Tek VIP Processor, and the Sakura Tissue-Tek paraffin embedding center. A variety of advanced programs and protocols for different types of tissue are available at the Breast Center Pathology Laboratory.

A Histobath and isopentane (2-Methyl butane) is used to freeze fresh tissue in cryoprotectant (e.g. O.C.T.) embedding media.

The Breast Center Pathology Core Lab performs microtomy on paraffin tissue blocks from around the world with the high precision Richard-Allan (formerly Zeiss) HM 315 microtomes and on frozen tissue with the Leica CM 1850 cryostat.

Paraffin microtomy is performed on routine as well as tissue microarray blocks. The thickness of sections ranges from 3-4 um for both H&E staining and immunohistochemistry. We also perform high precision sectioning using a Histocollimator for minute specimens. Tissue source species may involve human, mouse or rat.

Frozen tissue microtomy is performed for a variety of applications, from routine H&E staining to confocal microscopy. The section thickness can range from 4 um to 60 um.

It is performed on paraffin sections as well as frozen sections. We use Shandon Varistain (24-4) Automatic Stainer for H&E, and Hematoxylin counter staining on sections for immunohistochemical staining.

Currently the laboratory offers a limited number of special histochemical stains. These include:

• Hematoxylin counterstaining
• X-gal enzyme histochemistry on frozen sections
• Nuclear Fast Red Staining for Laser Capture Microdissection (LCM)
• Methyl Green Staining for LCM
• Others (special arrangement)

The laboratory has the capability to develop and/or implement new histochemical stains when required.