Which statement is true about clearing agents used for infiltration?

• A. Both Xylene and Tetrahydrofuran will clear tissue for infiltration.
• B. Only Xylene will clear tissue for infiltration.
• C. Only THF will clear tissue for infiltration.
• D. Neither will clear tissue.

Answer: (A)

Clearing agents for infiltration must be able to replace the alcohol that remains after dehydration and be miscible with paraffin so the tissue can be infiltrated smoothly. Xylene has been the traditional clearing agent because it effectively clears tissue and is compatible with paraffin. Tetrahydrofuran works similarly: it serves as a clearing agent because it is miscible with both water (and residual solvents) and paraffin, enabling a clean transition from dehydration to embedding. Because both can fulfill this role, either can be used to clear tissue for infiltration. Therefore the statement that both Xylene and Tetrahydrofuran will clear tissue for infiltration is true.