ASCP Tissue Processing 2 — Questions and Answers
Question 1: During dehydration, tissues are passed through graded alcohols starting from what concentration?
- 100%
- 95%
- 70% (Correct answer)
- 50%
Correct answer: 70%
Graded dehydration typically begins at 70% alcohol to avoid osmotic shock and cell distortion from sudden water removal.
Question 2: Which of the following is NOT a standard step in automated tissue processing?
- Fixation
- Dehydration
- Decalcification (Correct answer)
- Clearing
Correct answer: Decalcification
Decalcification is a separate pre-processing step performed on calcified tissues and is not part of the standard automated processing cycle.
Question 3: What temperature is paraffin wax typically maintained at during infiltration?
- 37°C
- 45°C
- 60°C (Correct answer)
- 75°C
Correct answer: 60°C
Paraffin wax is maintained at approximately 60°C during infiltration to keep it in its liquid state for proper tissue impregnation.
Question 4: What is the term for the process of surrounding embedded tissue with paraffin wax in a mold?
- Infiltration
- Embedding (Correct answer)
- Blocking
- Casting
Correct answer: Embedding
Embedding is the process of orienting tissue in molten paraffin within a mold to create a block for sectioning.
Question 5: Which fixative is preferred for electron microscopy due to superior ultrastructural preservation?
- 10% neutral buffered formalin
- Zenker's fixative
- Glutaraldehyde (Correct answer)
- Bouin's solution
Correct answer: Glutaraldehyde
Glutaraldehyde provides superior ultrastructural preservation by cross-linking proteins more effectively than formaldehyde for electron microscopy.
Question 6: What is the primary purpose of a tissue processor's vacuum function?
- To prevent overheating of tissue
- To speed reagent infiltration into dense tissues (Correct answer)
- To remove excess paraffin
- To filter contaminants from reagents
Correct answer: To speed reagent infiltration into dense tissues
Vacuum accelerates the infiltration of reagents, especially paraffin, into dense or fatty tissues by reducing air pockets.
ASCP Tissue Processing 2
During dehydration, tissues are passed through graded alcohols starting from what concentration?