ASCP Microtomy and Cryostat Techniques 2 — Questions and Answers
Question 1: What is the embedding medium used for frozen sections in a cryostat?
- Paraffin wax
- Agarose gel
- OCT (Optimal Cutting Temperature) compound (Correct answer)
- Glycerin
Correct answer: OCT (Optimal Cutting Temperature) compound
OCT compound supports tissue during cryosectioning by providing a firm matrix without ice crystal artifact formation.
Question 2: What microtomy artifact is caused by a nick or defect in the cutting blade?
- Chatter
- Venetian blind effect
- Score lines (linear streaks through the section) (Correct answer)
- Tissue folding
Correct answer: Score lines (linear streaks through the section)
A nicked or damaged blade creates linear streaks or score lines through the tissue section in the direction of cutting.
Question 3: Which of the following actions helps prevent tissue sections from folding during microtomy?
- Using a dull blade
- Warming the paraffin block
- Chilling the block face on ice before cutting (Correct answer)
- Increasing section thickness
Correct answer: Chilling the block face on ice before cutting
Chilling the block face hardens the paraffin slightly, reducing the tendency for thin sections to fold or wrinkle during cutting.
Question 4: What is the angle of the blade (clearance angle) typically set to on a rotary microtome?
- 0–2°
- 3–8° (Correct answer)
- 15–20°
- 25–30°
Correct answer: 3–8°
A clearance angle of 3–8° prevents the blade back from dragging on the tissue block while still allowing clean sectioning.
Question 5: Which stain is most commonly used for rapid intraoperative frozen section evaluation?
- Masson's trichrome
- Hematoxylin and eosin (H&E) (Correct answer)
- PAS stain
- Gram stain
Correct answer: Hematoxylin and eosin (H&E)
H&E is the standard rapid stain for frozen sections because it provides quick nuclear and cytoplasmic contrast for diagnostic evaluation.
Question 6: What is the purpose of the anti-roll plate in a cryostat?
- To hold the tissue block in place
- To prevent the cut section from rolling up (Correct answer)
- To cool the blade
- To clean the blade edge
Correct answer: To prevent the cut section from rolling up
The anti-roll plate guides and holds the cut section flat so it can be easily transferred to a glass slide.
ASCP Microtomy and Cryostat Techniques 2
What is the embedding medium used for frozen sections in a cryostat?