Tetrahydrofuran is described as which category?

• A. Dehydrant
• B. Clearing
• C. Infiltration/embedding
• D. Dehydrant and clearing aka universal solvent

Answer: (D)

Tetrahydrofuran acts as a universal solvent in tissue processing because it can operate in both water-rich and paraffin-rich environments. Its ability to mix with water and with paraffin allows it to replace water during dehydration and then clear the tissue so it is ready to be infiltrated with paraffin. That dual capability makes it suitable as both a dehydrating agent and a clearing agent, which is why the best description is that it serves as a dehydrant and clearing agent. In contrast, a dehydrant alone would not clear, a clearing agent alone wouldn’t remove water, and infiltration/embedding refers to the step of introducing paraffin, which THF facilitates but does not define as a single category.