Tissue Processing Flashcards
6 cards from real ASCP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Tissue Processing flashcards as text
Which reagent is used for decalcification of bone specimens?
Answer: EDTA or nitric acid
EDTA (chelating agent) and nitric acid are common decalcifying agents that remove calcium from bone to allow sectioning.
What is the consequence of over-decalcification on tissue?
Answer: Loss of nuclear staining and tissue damage
Over-decalcification damages nucleic acids and proteins, resulting in poor nuclear staining and compromised tissue morphology.
A tissue block shows a grainy, washed-out appearance after H&E staining. What processing artifact is most likely responsible?
Answer: Under-fixation
Under-fixation allows continued autolysis, resulting in poorly preserved, washed-out tissue morphology after staining.
What is the purpose of the post-fixation step using osmium tetroxide in electron microscopy preparation?
Answer: Fixation of lipids and enhancement of contrast
Osmium tetroxide fixes lipids and adds electron density to membranes, enhancing ultrastructural contrast for electron microscopy.
Which endpoint test is used to determine if decalcification is complete?
Answer: X-ray examination or chemical endpoint test
X-ray examination verifies calcium removal radiographically, while the chemical test detects calcium ions in the decalcifying solution.
What tissue processing problem is indicated by a crumbly, brittle paraffin block?
Answer: Over-processing (over-dehydration or excessive paraffin heat)
Over-processing desiccates tissue, making it brittle and causing the block to crumble during sectioning.