True or False: Low viscosity clearing agents clear tissues faster than high viscosity clearing agents at 20°C.

• A. True
• B. False
• C. Not applicable
• D. Sometimes

Answer: (A)

Diffusion into tissue happens more quickly when the solvent is less viscous. At a fixed temperature, the diffusion coefficient increases as viscosity decreases, so a low-viscosity clearing agent penetrates tissue and displaces alcohol faster than a high-viscosity one. Because the temperature is the same (20°C), comparing clearing agents by viscosity shows that the lower-viscosity agent clears more quickly. Of course, other factors like miscibility with the surrounding medium and tissue type can influence overall clearing, but the basic principle makes the statement true.