Processing Flashcards
Vocab
Universal solvent
Reagents that avoid the use of 2 solutions. They can perfom dehydration & clearing steps. Miscible with water-based solutions and paraffin.
Examples:
Dioxane
Tertiary butanol
Tetrahydrofuran
What are the PEL for each of the following dehydrating reagents:
Ethyl alcohol
Methyl alcohol
Isopropyl alcohol
Butyl alcohol
Acetone
Ethyl = 1000 ppm
Methyl = 200 ppm
Isopropyl = 400 ppm
Butyl = 100 ppm
Acetone = 1000 ppm
Troubleshooting
Most common problems encoutered in processing are?
(2 answers)
Overprocessing & Underprocessing
Troubleshooting
If you encounter dry/brittle/powdery tissue, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Overhydration
Corrective Actions:
-Soak block in ice water before cutting & cut carefully, may produce better sections
-Reduce dehydration time/tem on tissue processing protocol
Compare to microchatter, & parched earth
Troubleshooting
If you encounter microchatter what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Overdehydration
Corrective Actions:
-Soak block in ice water before cutting & cut carefully, may produce better sections
-Reduce dehydration time/tem on tissue processing protocol
Compare to Dry/brittle/powdery tissue & parched earth
Troubleshooting
If you encounter parched earth tissue what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Overhydration
Corrective Actions:
-Soak block in ice water before cutting & cut carefully, may produce better sections
-Reduce dehydration time/tem on tissue processing protocol
Compare to microchatter & dry/brittle/powdery tissue
Troubleshooting
If you encounter cell shrinkage what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Overdehydration
Corrective Actions:
-Reduce dehydration time/tem on tissue processing protocol
Compare to microchatter & dry/brittle/powdery tissue
Troubleshooting
If you encounter a block where the central tissue is not sectioning, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Causes:
-Underhydration
-Lack of infiltration
-Incorrect processing protocol used
Corrective Actions:
-Reprocess tissue
-Increase dehydration time on tissue processing protocol
Compare to concave & white bulding tissue
Troubleshooting
If you encounter a block where the tissue apears concave, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Causes:
-Underhydration
-Lack of infiltration
-Incorrect processing protocol used
Corrective Actions:
-Reprocess tissue
-Increase dehydration time on tissue processing protocol
Compare to central area non-sectioning & white bulding tissue
Troubleshooting
If you encounter a block where the tissue apears white and expands/bludges out, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Excessive soadking during microtomy
Corrective Action: Limit time of ice bath soaking
Compare to central area non-sectioning & concave tissue
Troubleshooting
If you encounter H&E sections where the epithelial nuclei look washed out, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Causes:
-Contaminated clearing/infiltration reagents
-Tissue not fully dehydrated
Corrective Actions:
-Reprocess tissue
-Change dehydration, clearing, & infiltration reagents on processor
Compare to nuclear bubbling & dark/hazy blue nuclei
Troubleshooting
If you encounter H&E sections with nuclear bubbling, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Causes:
-Incomplete fixation
-Excessive heat during dring slide
Corrective Action: Ensure minimum of 6-8hrs of fixation before processing
Compare to washed out epithelial nuclei & dark/hazy blue nuclei
Troubleshooting
If you encounter dark/hazy blue nuclei, what are the casue(s) and corrective action(s)?
From Self Instruction textbook, notes & etc
Cause: Excessive heat during processing
Corrective Action: Heat should only be used on paraffin sations during processing at 2-4C above melting point of paraffin
Compare to washed out epithelial nuclei & nuclear bubbling
Troublshooting
If you encounter bone dust on a slide, what are the casue(s) and corrective action(s)?
Cause: Bone dust pressed into the surfaces during gross sectioning
Corrective Actions: Mostly preventative
-Use saw with a diamond blade
-Trim bone surfaces after decalcification but before processing
Troublshooting
If you encounter hard/crunchy tissue, what are the casue(s) and corrective action(s)?
Cause: Inadequate decal treatment
Corrective Actions:
-Surface decalcification at microtomy
-Reprocessing with extended preprocessing decalcification
-Check endpoint of decalcificationwith radiography when in dobut (preventative)
Troublshooting
If you encounter difficult microtomy of decalcified tissue and/or loss of nuclear detail, what are the casue(s) and corrective action(s)?
Cause: Excessive decal treatment
Corrective Actions:
-Submit additional tissue if possible (retry with new sample)
-Check endpoint of decal with radiography when in doubt
Troublshooting
If you encounter frozen section of skeletal muscle fibers with apparent holes, what are the casue(s) and corrective action(s)?
Cause: Freezing artifact from improper freezing of tissue that make histochemical studies worthless and/or can be mistaken for vacuoles in some muscle diseases.
Corrective Actions: None
Preventable Steps:
-Use heat extractor
-Freeze with isopentane chilled to -150C
-Use other method of rapid freezing
-Ensure tissue is not immersed in saline before freezing
Troublshooting
Is the image likely an example of a routine processing issue and a frozen processing issue?
Image is an example of ice crystal artifact in a frozen section. Irregularly spaced holes. Source tissue given was brain.
Cause: Freezing artifact from improper freezing of tissue that make it diagnostically worthless.
Corrective Actions: None
Preventable Steps:
-Specficially for brain, avoid specimen sitting in saline solution for longer than 10min before freezing
-Use heat extractor
-Freeze with isopentane chilled to -150C
-Use other method of rapid freezing
-Ensure tissue is not immersed in saline before freezing
Troublshooting
Is the image likely an example of a routine processing issue or a frozen processing issue?
Image is an example of cell shrinkage artifact in a routine section. Regularly spaced holes.
Cause: Overdehydration
Corrective Actions: Mostly just preventable step
-Reduce dehydration time/temperatures on the processing protocol
