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46 Cards in this Set
- Front
- Back
Front (Term) |
Fragmented and torn |
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Rotary microtome uses what medium? |
Paraffin Glycol methacrylate |
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CNS stands for |
Central nervous system |
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What microtome is used for a research |
Sliding Ultramicrotome |
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Microtomy process examination includes |
1) check accession # (slide & block) 2) check embedding was done correctly 3) check stain order & tissue type |
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Microtomy process for orientation block into chuck: |
1) Cut softest to hardest: go through subsurface 2) make edges parallel to blade (makes ribboning easier) |
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Rough cut or face into block by |
15-30 micrometers |
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When facing in to the block |
Ensure all tissue is exposed Look for artifacts |
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In order to obtain a good ribbon |
Rotate ~1 revolution per second Light blow ribbon to help decompress / reduce static |
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A warm water bath helps reduce.. |
Ribbon folds |
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Drying oven temperature should be kept at |
Above paraffin melting point |
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Cleaning / skimming water bath helps with |
Preventing floaters artifacts Prevents misdiagnosis Prevents cross contamination |
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When cleaning the microtome: (QC practices) |
Use soft brush for loose paraffin Use moist xylene cloth to dissolve paraffin wax Cover when not in use Lubricate according to manufacturers Document when cleaned or serviced |
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The proper knife tilt or clearance angle should be: |
3-8° |
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Two blade angles |
Bevel Knife tilt/Clearance |
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Use a sharp fresh blade to: |
Reduce amount of artifacts |
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Ergonomics for microtomy includes |
Use full arm when rotating Keep steady posture Position water bath to easily accessible |
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Keep waterbath at |
5-10° C below paraffin mp |
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Routine sections should be cut: |
4-6 micrometers |
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Kidney stain should be cut |
2-3 micrometers |
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Amiloyd stains should be cut |
8-10 micrometers |
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Keep blocks on ice to |
Easier cuts Add moisture to block (over processed or over dehydrated) |
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E) All of the above |
All of the above |
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knife lines can be caused by |
Defect in the blade edge Hard particle in block (staple, calcium deposit |
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Knife line corrective actions include |
Move/change blade Remove defect in block (staple, calc) |
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How to prevent knife lines |
Remove defects when grossing Ensure your using a fresh knife Clean off old paraffin wax on and behind knife |
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Crooked ribbons can be caused by |
Top and bottom edges aren’t parallel Uneven chilling Not parallel to the blade |
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How to prevent crooked ribbons |
Ensure edges are parallel Ensure there’s no movement with the blade Block gets chilled evenly |
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Uneven sectioning is cause by |
Chuck not parallel to the blade |
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Holes in sections can be caused by |
Block is faces too aggressively (tissue chips out, tear away tissue) Excessive dehydration Tissue types have holes (lungs) |
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How to prevent holes in section |
Slower face block (smaller micrometers cuts) Ribbon until holes disappear (if enough tissue) Soak block in Ice before sectioned |
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Ribboning failure is caused by |
Dull blade (most common) Room temp Too much blade tilt Paraffin too hard |
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Possible causes of “washboarding” |
Very hard tissues (uterus/bone) Old/loose microtome parts |
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Prevention for washboarding includes: |
Need enough support paraffin/Correct mold size (overcrowding) Keep block & blade tight Decrease blade tilt |
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Possible causes from chatter |
Overprocessed Too much blade tilt Dull blade (change blade frequent) Cutting too fast |
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Prevention for chatter |
Correct processing schedules Soak in ice water Decrease blade tilt Slow down |
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Causes / prevention for varied thickness |
Too little blade tilt / increase tilt Loose microtome parts / maintenance of microtome |
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Causes for wrinkles or compressed sections |
Dull blade Build up on blade Too little knife tilt Too fast of cutting Room temp = too warm |
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Torn sections caused by |
Under processing Leaving tissue is water bath too long or water bath temp too high |
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Temp for most tissues on cryostat should be held at |
-20° C |
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Temp used for breast tissue on cryostat |
-25° C |
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Temp used for brain, liver, spleen, lymph node on cryostat |
-10° C |
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Steps to cryotomy |
1) cryombed fresh tissue 2) rough out / face into flat sections 3) obtain sections directly onto slides |
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Front (Term) |
Swcrions |
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Front (Term) |
Sections uneven thickness |
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Front (Term) |
Cut too thick of levels |
