Histology Certification Staining Methods 2 — Questions and Answers
Question 1: Which stain is specifically used to identify reticular fibers in tissue sections?
- Masson's trichrome
- Gordon and Sweet's reticulin stain (Correct answer)
- Alcian blue
- Orcein stain
Correct answer: Gordon and Sweet's reticulin stain
Gordon and Sweet's reticulin stain uses silver impregnation to selectively blacken reticular fibers.
Question 2: What color do elastic fibers appear when stained with Verhoeff's Van Gieson (VVG) stain?
- Red
- Blue
- Black (Correct answer)
- Yellow
Correct answer: Black
Verhoeff's Van Gieson stain colors elastic fibers black while collagen appears red and muscle appears yellow.
Question 3: The PAS (Periodic Acid-Schiff) reaction detects which type of tissue component?
- Nucleic acids
- Lipids
- Polysaccharides and glycoproteins (Correct answer)
- Acidic proteins
Correct answer: Polysaccharides and glycoproteins
PAS oxidizes vicinal diols in polysaccharides and glycoproteins to aldehydes, which then react with Schiff reagent to produce a magenta color.
Question 4: Which fixative is most compatible with enzyme histochemistry?
- 10% neutral buffered formalin
- Bouin's solution
- Glutaraldehyde
- Cold acetone or unfixed frozen sections (Correct answer)
Correct answer: Cold acetone or unfixed frozen sections
Cold acetone or unfixed frozen sections preserve enzyme activity, whereas aldehyde fixatives typically inactivate enzymes.
Question 5: In the Ziehl-Neelsen stain, what property of Mycobacterium tuberculosis allows it to retain carbol fuchsin?
- Its thick peptidoglycan wall
- High lipid content of its cell wall (mycolic acids) (Correct answer)
- Its capsule polysaccharides
- Its flagellar proteins
Correct answer: High lipid content of its cell wall (mycolic acids)
The high mycolic acid content of mycobacterial cell walls makes them acid-fast, retaining carbol fuchsin even after acid-alcohol decolorization.
Question 6: Sudan black B stain is used to demonstrate which tissue component?
- Glycogen
- Lipids and fatty acids (Correct answer)
- Collagen
- Nucleic acids
Correct answer: Lipids and fatty acids
Sudan black B dissolves in and stains lipids dark blue-black, making it useful for identifying fat droplets and lipoproteins.
Question 7: What is the role of mordant in Hematoxylin staining?
- It decolorizes background tissue
- It acts as a link between the dye and tissue component (Correct answer)
- It oxidizes hematoxylin to hematin
- It increases tissue permeability
Correct answer: It acts as a link between the dye and tissue component
A mordant (typically alum) forms a coordination complex bridging hematoxylin to negatively charged tissue components like nucleic acids.
Histology Certification Staining Methods 2
Which stain is specifically used to identify reticular fibers in tissue sections?