Histology Certification Staining Methods 3 — Questions and Answers
Question 1: Which stain is the gold standard for identifying amyloid deposits in tissue?
- Congo red (Correct answer)
- Prussian blue
- Masson's trichrome
- Giemsa
Correct answer: Congo red
Congo red stains amyloid salmon-pink and produces pathognomonic apple-green birefringence under polarized light.
Question 2: The Grimelius stain is used to demonstrate which cell type?
- Mast cells
- Plasma cells
- Argyrophilic neuroendocrine cells (Correct answer)
- Goblet cells
Correct answer: Argyrophilic neuroendocrine cells
Grimelius is an argyrophilic silver stain that highlights neuroendocrine cells by reducing silver ions in the presence of an exogenous reducing agent.
Question 3: What color does cartilage matrix appear when stained with Alcian blue at pH 2.5?
- Red
- Blue (Correct answer)
- Yellow
- Green
Correct answer: Blue
Alcian blue at pH 2.5 stains sulfated and carboxylated glycosaminoglycans in cartilage matrix blue.
Question 4: Which silver stain technique is most commonly used to demonstrate fungal elements in tissue?
- Warthin-Starry stain
- Gomori methenamine silver (GMS) (Correct answer)
- Bielschowsky stain
- Steiner stain
Correct answer: Gomori methenamine silver (GMS)
Gomori methenamine silver (GMS) stain blackens fungal cell walls against a pale green background, making it the standard for fungal detection.
Question 5: In Masson's trichrome staining, what color does smooth muscle appear?
- Blue
- Green
- Red/pink (Correct answer)
- Black
Correct answer: Red/pink
In Masson's trichrome, muscle fibers stain red or pink with acid fuchsin, while collagen stains blue or green depending on the variant.
Question 6: The Fontana-Masson stain is used to detect which pigment?
- Lipofuscin
- Hemosiderin
- Melanin (Correct answer)
- Bilirubin
Correct answer: Melanin
Fontana-Masson is an argentaffin silver stain that reduces silver ions without exogenous reducer, selectively blackening melanin granules.
Question 7: What does 'metachromasia' mean in histological staining?
- The stain only works on fixed tissues
- The tissue component stains a different color than the dye solution itself (Correct answer)
- Two dyes are applied simultaneously
- The stain fades rapidly after application
Correct answer: The tissue component stains a different color than the dye solution itself
Metachromasia occurs when a dye (e.g., toluidine blue) binds polyanionic tissue components so densely that its absorption spectrum shifts, producing a different color (e.g., purple-red instead of blue).
Histology Certification Staining Methods 3
Which stain is the gold standard for identifying amyloid deposits in tissue?