If microtomy sections lift from the blade as the block is raised, the most likely cause is which?

• A. A dull blade
• B. An excessively sharp blade
• C. A too-narrow blade angle
• D. A misaligned stage

Answer: (A)

The cutting edge condition is the key factor here. A dull blade fails to slice cleanly through the tissue, causing tearing and increased friction as the block is advanced. This damaged edge makes the section cling to the blade edge, so when you raise the block the section tends to lift off the blade rather than transferring smoothly into the water bath. Replacing or resharpening the blade restores a clean shear and prevents this lifting artifact. If the blade were excessively sharp or the angle too narrow, you’d see different issues such as ultra-thin ribbons or increased chatter; a misaligned stage would cause broader alignment problems across ribbons rather than a consistent lift-off at the blade.