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Knife lines

Incomplete and complete skin sections

Skin Sectioning Troubleshooting

Below is a troubleshooting chart that can be applied to various tissue types, not just skin samples. Once the problem or artifact is identified, possible sources are investigated and solutions applied to prevent the artifacts. The artifacts listed are evident on the stained slide, but most are noticed during microtomy and should be resolved BEFORE the staining process.

Artifact/ProblemSourceSolution
Wrinkles
  • Competing layers of cells (muscle, elastic, fat, connective)
  • Cool water bath
  • Brief time on water
  • Increase water bath temperature
  • Allow more time for tissue section to "relax" on the water
  • Stretch the ribbon gently
Chatter/washboard
/venetian blinds
  • Dry, over-dehydrated tissue
  • Rapid cutting speed
  • Vibration caused by loose knife, block, or microtome parts
  • Knife clearance angle too big
  • Reduce dehydration time in processing
  • Soak blocks in ice water
  • Decrease cutting speed
  • Tighten knife, block, and microtome parts
  • Decrease knife clearance
Incomplete tissue section
  • Improper embedding; tissue not flat
  • Facing/cutting too shallow
  • Improper processing of tissue (fat dissolves/explodes)
  • Rough and rapid course facing leads to chunks of tissue popping out of block, leaving moth holes
  • Re-embed tissue flat
  • Cut deeper into block to reveal entire section
  • Increase processing time for fatty specimens
  • Reduce facing speed and depth to gently expose the tissue in the block
Thick/thin
  • Rapid cutting speed
  • Very slow cutting speed; tissue warms and expands
  • Loose block, knife, or microtome parts
  • Decrease cutting speed
  • Increase cutting speed to prevent tissue expansion during slow cutting
  • Tighten block, knife, and microtome parts
Knife marks/scratches
  • Hard materials found in tissue such as calcifications, hair, nail, or foreign material
  • Knife edge damaged
  • Debris built up on knife edge
  • Decalcify/soften tissue properly, remove foreign materials if possible
  • Replace knife
  • Keep knife clean
Floaters
  • Tech's skin cells fall on water or slide
  • Fragments of tissue from previous samples
  • Fibers/dust contaminate water or slides
  • Tech should not lean over water bath or handle slides with un-gloved hands
  • Clean water bath after each use
  • Skim surface of water between each block