Which statement is false?

• A. Sections processed by the cellodin method show less shrinkage than paraffin.
• B. Frozen sections are specified for demonstration of most enzymes.
• C. Overheating paraffin infiltration causes shrinkage and over hardening.
• D. A chelating agent exchanges another ion for calcium.

Answer: (D)

Chelating agents work by forming stable complexes with calcium ions, effectively removing calcium from the tissue during decalcification. They do not exchange one ion for calcium; they bind calcium. So the idea of an ion-for-ion exchange is incorrect. The other statements fit what’s known: the celloidin method generally results in less shrinkage than paraffin, frozen sections are used to demonstrate enzyme activity, and overheating paraffin infiltration can cause shrinkage and over-hardening.