Histology

• What is the principle of physical staining?

  Dyes are dissolved or impregnated onto tissue
• What is an example of a physical staining technique?

  Fat staining with selectively precipitated silver
• What does physico-chemical staining involve?

  Formation of intermolecular bonds between dye and tissue
• What is an example of a physico-chemical staining technique?

  Hematoxylin and eosin staining
• What occurs during a histochemical staining process?

  A chemical reaction generates a new color
• What is the most commonly used staining technique?

  Hematoxylin-Eosin staining
• What does hematoxylin stain in cells?

  Acidic cell components dark blue/purple
• What type of molecules does hematoxylin stain?

  Basophilic molecules like DNA and RNA
• What does eosin stain in cells?

  Basic cell components in pink
• What type of molecules does eosin stain?

  Eosinophilic molecules like proteins
• What does PAS staining target?

  Nuclei and carbohydrates
• What color does PAS stain carbohydrates?

  Magenta
• What is the chemical reaction in PAS staining?

  Aldehyde groups react with Schiff’s reagent
• What does Masson Trichrome stain?

  Collagen fibers in blue or green
• What color does Van Gieson staining give to collagen fibers?

  Red
• What does Verhoeff-van Gieson’s stain target?

  Elastic fibers in black
• What color does GALLEGO stain elastic fibers?

  Fuchsia
• What is the purpose of silver staining?

  To stain reticular fibers black or brown
• What does Ziehl Neelsen staining detect?

  Mycobacteria
• What color do mycobacteria appear in Ziehl Neelsen staining?

  Red magenta on a blue background
• What does Warthin Starry staining involve?

  Staining with silver ions
• What does PAS staining detect in fungi?

  Polysaccharide walls in magenta
• What is the basis of immunohistochemistry (IHC)?

  Use of antibodies to identify proteins
• What do antibodies bind to in IHC?

  Specific antigens
• What does immunofluorescence involve?

  Fluorescence signal to analyze cells

  
• What is the function of a fluorescence microscope?

  To label proteins or molecules
• What does a confocal fluorescence microscope improve?

  Resolution of fluorescent samples
• What does Black Sudan stain?

  Nuclei and cytoplasm red, lipids black
• What does Oil Red O stain?

  Stains lipids in red
• What indicates a metachromatic reaction?

  Different staining of tissue structure
• What color do metachromatic dyes stain nuclei?

  Purple-blue
• What do mast cell granules accumulate?

  Inflammatory mediators like histamine
• Where do mast cells derive from?

  Blood monocytes