ASCP Microtomy and Cryostat Techniques 1 — Questions and Answers
Question 1: What is the standard section thickness used for routine paraffin H&E sections?
- 1–2 µm
- 4–5 µm (Correct answer)
- 10–12 µm
- 20–25 µm
Correct answer: 4–5 µm
Routine paraffin sections are cut at 4–5 µm to allow adequate light transmission and single-cell-layer evaluation.
Question 2: What is the purpose of the water bath used during paraffin sectioning?
- To fix sections before mounting
- To float and flatten sections by removing compression wrinkles (Correct answer)
- To stain sections
- To remove paraffin from sections
Correct answer: To float and flatten sections by removing compression wrinkles
The water bath (typically 40–45°C) allows compressed sections to expand and flatten before being picked up on slides.
Question 3: What type of blade is used for cutting frozen sections on a cryostat?
- High-profile disposable blade
- Low-profile disposable blade (Correct answer)
- Carbide-tipped blade
- Diamond blade
Correct answer: Low-profile disposable blade
Low-profile disposable blades are used in cryostats because they fit the cryostat microtome head and are designed for frozen tissue.
Question 4: What is the primary advantage of frozen sections over paraffin sections during intraoperative consultation?
- Superior morphological detail
- Rapid turnaround time for immediate surgical decisions (Correct answer)
- Better antigen preservation for IHC
- Easier to cut thin sections
Correct answer: Rapid turnaround time for immediate surgical decisions
Frozen sections can be prepared in 10–15 minutes, allowing surgeons to receive immediate pathological guidance during an operation.
Question 5: What is 'chatter' in microtomy?
- Tissue folding during cutting
- Parallel lines or waves across a section due to vibration (Correct answer)
- Incomplete paraffin removal
- Tissue tearing at edges
Correct answer: Parallel lines or waves across a section due to vibration
Chatter produces parallel lines across the section caused by vibration between the blade and the block during cutting.
Question 6: What temperature range is a cryostat chamber maintained at for optimal sectioning of most tissues?
- -5°C to -10°C
- -15°C to -25°C (Correct answer)
- -30°C to -40°C
- 0°C to -5°C
Correct answer: -15°C to -25°C
A cryostat chamber maintained at -15°C to -25°C provides the optimal firmness for most tissues without making them too brittle.
ASCP Microtomy and Cryostat Techniques 1
What is the standard section thickness used for routine paraffin H&E sections?