PURPOSE: Used to differentiate between collagen and smooth muscle in tumors, and the increase of collagen in diseases such as cirrhosis. Routine stain for liver and kidney biopsies. PRINCIPLE: As the name implies, three dyes are employed selectively staining muscle, collagen fibers, fibrin, and erythrocytes.

Mason’s Trichrome stain is used to highlight connective tissue fibers in a tissue section. Collagen fibers are stained a blue hue, nuclei a blue-black, and cytoplasm, keratin, and muscle fibers a range of pink to red hues.

The reticulin stain is extensively used in the histopathology laboratory for staining liver specimens, but can also be used to identify fibrosis in bone marrow core biopsy specimens.

Histological staining is a series of technique processes undertaken in the preparation of sample tissues by staining using histological stains to aid in the microscope study (Anderson, 2011).

“Special stains” are processes that generally employ a dye or chemical that has an affinity for the particular tissue component that is to be demonstrated. They allow the presence/or absence of certain cell types, structures and/or microorganisms to be viewed microscopically.

Orcein stain is a staining technique used for the visualization of hepatitis B surface antigens (HBsAg), elastic fibers and copper-bound proteins. Viral particles present inside host cells are called viral inclusion bodies.

The most common stains used in histology are the following:

• Routine stains. Haematoxylin & Eosin.
• Special stains. Van Gieson. Toluidine Blue. Alcian Blue. Giemsa. Reticulin. Nissl. Orcein. Sudan Black B. Masson’s Trichrome. Mallory’s Trichrome. Azan Trichrome. Cason’s Trichrome. Periodic Acid Schiff. Weigert’s Resorcin Fuchsin.

Hematoxylin and Eosin (H&E) staining is used routinely in histopathology laboratories as it provides the pathologist/researcher a very detailed view of the tissue. It achieves this by clearly staining cell structures including the cytoplasm, nucleus, and organelles and extra-cellular components.

). Because fibrosis is often a response to tissue damage (it is meant to replace damaged tissue when repair is not possible), it is often associated with inflammation. Fibrosis can be confirmed with special stains for collagen. With the Mason’s trichrome staining technique, mature collagen stains blue ( Figure 2

Because fibrosis is often a response to tissue damage (it is meant to replace damaged tissue when repair is not possible), it is often associated with inflammation. Fibrosis can be confirmed with special stains for collagen. With the Mason’s trichrome staining technique, mature collagen stains blue ( Figure 2 ).

Special stains are histochemical stains that have an affinity for particular extra/intra-cellular structures, or particular microorganisms. What are the most common special stains used to assess liver biopsies?

Because fibrosis is often a response to tissue damage (it is meant to replace damaged tissue when repair is not possible), it is often associated with inflammation. Fibrosis can be confirmed with special stains for collagen.