ASCP Hematoxylin and Eosin Staining 3 — Questions and Answers
Question 1: In a well-stained H&E section, red blood cells (RBCs) should appear what color?
- Blue-purple
- Bright red/orange (Correct answer)
- Green
- Colorless
Correct answer: Bright red/orange
RBCs lack nuclei and stain brightly eosinophilic (bright red to orange) due to their hemoglobin content.
Question 2: What is the purpose of rehydration after deparaffinization before H&E staining?
- To remove residual xylene and prepare tissue for aqueous dyes (Correct answer)
- To fix tissue before staining
- To remove excess eosin
- To improve section adherence
Correct answer: To remove residual xylene and prepare tissue for aqueous dyes
After xylene deparaffinization, tissue must be rehydrated through descending grades of alcohol to prepare it for aqueous hematoxylin and eosin solutions.
Question 3: What does basophilic staining indicate in H&E histology?
- Affinity for eosin (acidic dye)
- Affinity for hematoxylin (basic dye) (Correct answer)
- Lack of staining
- Affinity for both dyes equally
Correct answer: Affinity for hematoxylin (basic dye)
Basophilic structures have a negative charge that attracts the basic dye hematoxylin, staining them blue-purple.
Question 4: What color does mucin typically stain in a routine H&E preparation?
- Deep blue-purple
- Bright pink
- Pale blue or clear (Correct answer)
- Yellow
Correct answer: Pale blue or clear
Mucin stains pale blue or is nearly clear in routine H&E, which is why special stains like PAS or Alcian blue are used to highlight it.
Question 5: What is the function of Scott's tap water (or ammonia water) in the H&E staining process?
- Dehydration step
- Bluing agent to convert hematoxylin complex to blue (Correct answer)
- Differentiation agent
- Eosin rinse
Correct answer: Bluing agent to convert hematoxylin complex to blue
Scott's tap water (magnesium sulfate and sodium bicarbonate) raises the pH, converting the brownish-red hematoxylin complex to its characteristic blue color.
Question 6: Which of the following is a quality control indicator for an H&E stained section?
- All cell types stain uniformly one color
- Crisp blue nuclei with pink cytoplasm and no background staining (Correct answer)
- Collagen stains blue
- Nuclei stain red and cytoplasm stains blue
Correct answer: Crisp blue nuclei with pink cytoplasm and no background staining
A well-stained H&E section shows sharp blue-purple nuclei, pink cytoplasm, and clean background without precipitate or uneven staining.
ASCP Hematoxylin and Eosin Staining 3
In a well-stained H&E section, red blood cells (RBCs) should appear what color?