The issue in the image can be corrected by which adjustment?

• A. Retracting the block holder shaft
• B. Replacing the slide
• C. Changing the staining solution
• D. Using a new fixative

Answer: (A)

In microtomy, clean sections depend on proper clearance and alignment between the knife and the tissue block. If the block is positioned too far forward toward the blade or not properly retracted, the blade can dig into the paraffin, causing irregular edges or chatter in the ribbon. Retracting the block holder shaft reduces that forward pressure, increasing the clearance so the blade can shear the tissue more smoothly. This change directly targets the mechanical cutting process and is a common fix for artifacts seen in the section, such as roughness, tearing, or inconsistent section thickness.

Changing the staining solution or fixative would alter color or tissue morphology, not the physical quality of the cut. Replacing the slide wouldn’t address a problem rooted in how the tissue is being sectioned.