Paraffin Impregnation Troubleshooting in Histology
This quiz troubleshoots common issues in paraffin impregnation, a crucial step in histology specimen preparation. It identifies causes and solutions to problems like contaminated wax, incomplete impregnation, and inadequate cooling.
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Paraffin Impregnation Troubleshooting in Histology
Quiz • 18 Questions
Study Notes
2 min • Summary
Paraffin Impregnation Troubleshooting in Histology - Podcast
Podcast
Materials
List of Questions18 questions
- Question 1
- Paraffin block is warm and soft
- Microtome set screw is loose
- Knife is not parallel to the block
- Tilt of knife is too vertical
- Question 2
- Insufficient paraffin impregnation
- Contaminated wax
- Tough keratin component of certain tissues
- Incomplete clearing
- Question 3
- Re-embed in freshly filtered wax
- Hone and strop the knife
- Re-trim the block
- Readjust knife and block
- Question 4
- Prolong the clearing process up to 12 hours
- Change the paraffin at least once before blocking
- Use a different type of wax
- Increase the temperature of the embedding oven
- Question 5
- Knife edge is coated with paraffin
- Tilt of knife is too great
- Blocks are too hard
- Microtome set screw is loose
- Question 6
- It is a poor fat solvent
- It is too expensive
- It is too toxic
- It is not available
- Question 7
- 10% formalin
- Distilled water
- Absolute ethanol
- 4% aqueous phenol
- Question 8
- Coat horizontal edges of the block with wax of lower melting point
- Reduce the tilt of the knife
- Re-trim the block
- Soften the blocks in detergent or phenol
- Question 9
- To ensure complete fixation
- To prevent contamination
- To facilitate easy reagent action
- To reduce the cost of reagents
- Question 10
- Bubble or dirt formed in the embedding medium
- Knife edge is dull
- Tilt of knife is too great
- Blocks are too large
- Question 11
- Cool/change the room temperature or cool the block in ice water
- Trim the block edges until they are parallel
- Reduce the tilt of the knife
- Re-sharpen the knife using a knife back or automatic knife sharpener
- Question 12
- Isopropanol
- Distilled water
- Methanol
- Acetone
- Question 13
- Insufficient fixation
- Overheated paraffin oven
- Inadequate dehydration
- Incomplete removal of water during dehydration
- Question 14
- Tissue becomes brittle and hard
- Tissue shrinks away from wax when trimmed
- Insufficient dehydration and incomplete clearing and impregnation
- Tissue is soft when block is trimmed
- Question 15
- Insufficient clearing
- Presence of airholes in the tissue
- Tissue is too soft
- Overheated paraffin oven
- Question 16
- Prolonged dehydration
- Prolonged fixation
- Soaking in a small dish or bowl containing water with detergent
- Repeat dehydration with absolute alcohol then clear again
- Question 17
- Inadequate processing of fatty tissues
- Moisture in the paraffin block
- Overheated paraffin oven
- Insufficient dehydration
- Question 18
- Tissue is soft when block is trimmed
- Clearing agent turns milky as soon as tissue is placed in it
- Insufficient clearing and impregnation
- Tissue shrinks away from wax when trimmed