Which statement about overheating paraffin during infiltration is true?

• A. Overheating the paraffin used for infiltration will cause tissue shrinkage and over hardening.
• B. Overheating paraffin has no effect on tissue.
• C. Overheating paraffin makes tissues more pliable.
• D. Overheating paraffin improves infiltration without drawbacks.

Answer: (A)

Controlling the temperature of the embedding medium is essential because paraffin interacts with the tissue as it infiltrates and solidifies. If paraffin is overheated, it becomes too fluid and can drive out water and some tissue components too aggressively. As the tissue loses water and the wax solidifies, the tissue shrinks and becomes overly hard or brittle. That combination—shrinkage plus hardening—produces artifacts and makes sections difficult to cut cleanly. So overheating the paraffin indeed causes tissue shrinkage and over hardening, which is why that statement is true. The other options aren’t correct because overheating does affect tissue, it doesn’t make tissues more pliable, and it doesn’t improve infiltration without drawbacks.