FAQ Microtomes & Sectioning
Sectioning Problems
   
01.   How can it be avoided that sections are compressed/wrinkled or even jammed?
   
  1. You might use a dull blade/knife: Please use another area of the cutting edge or a new blade/knife.
  2. The specimen might be too warm: Please cool the specimen prior to sectioning by using a cold plate, iced water or ice cub read more ...
02.   How can it be avoided that thick/thin sections are produced, the section thickness varies from one section to another or even every second section is skipped?
   
  1. Insufficient clamping of the blade, the knife holder, the specimen and/or the orientation might cause this problem: Please check if all levers are locked and screws are tightened.

    Cassette related problems?

    Underfilling of th read more ...

03.   How to avoid chatter (Venetian Blind effect/washboard/undulations)?
   
  1. The clearance angle is too big: Clearance angle adjustment; systematically decrease the clearance angle until the optimum adjustment is obtained.
  2. A damage to the pressure plate exists (bent/nicked): Replace the pressure read more ...
04.   How can "stripes/scratches" or splits in sections be avoided?
   
  1. Paraffin might have accumulated at the rear of the back plate of the disposable blade holder or on the front or back of the knife edge: Please remove paraffin debris regularly from the pressure plate. Clean knife with a cloth mois read more ...
05.   What can I do if the sections do not form ribbons?
   
  1. The specimen block is too cold: Warm up the specimen.
  2. The paraffin is too hard: Re-embed the specimen in softer paraffin. Immerse the entire block in softer paraffin - a thin "glued on" layer will stick to the block. read more ...
06.   How can I avoid curved ribbons?
   
  1. The edges of the block are not parallel: Please trim the block edges to be parallel.
  2. The block is not parallel to the knife edge: Align the block to the knife edge.
  3. There might be irregularities in the knife e read more ...
07.   What can I do if the sections disintegrate or the embedding material comes apart from the tissue specimen itself?
   
  1. The tissue might be incompletely dehydrated and/or poorly infiltrated: If possible, try re-embed the sample.
  2. The tissue has remained too long in the paraffin bath or the paraffin bath was too hot: In this case, the damage read more ...
08.   What can I do if sections splinter?
    The specimen is too cold: Warm up the specimen.
09.   How can I avoid that sections are sticking to the pressure plate?
   
  1. There might be too much paraffin: Clean the knife with a swab moistened with xylene. Stroke the swab in an upward motion away from the blade edge, not down on the blade edge.
  2. The pressure plate is dirty: Clean plate with read more ...
10.   What can I do if the sections are not properly flattened?
   
  1. The specimen might not be cold enough: Select a lower temperature.
  2. The specimen surface is rather large: Trim the specimen parallel and increase the section thickness.
  3. The knife clearance angle is not correctl read more ...
11.   What can I do to avoid noise during sectioning (knife produces a screeching noise) and/or sections with chatter marks or scratches?
   
  1. The sectioning speed is too high: Please lower the sectioning speed.
  2. The sectioning thickness is too high: Please lower the thickness.
  3. The clearance angle is too wide: Please try systematically to reduce the c read more ...
12.   What is to do if the specimen is picked up in the return stroke of the specimen arm?
   
  1. Static electricity charge may be built up on the knife holder or the specimen head: Adjust temperature or humidity level in the room. Use an ionizer to neutralize the static charge. Clean components of the microtome with alcohol. read more ...