Which solvent is an aromatic hydrocarbon commonly used as a clearing agent?

• A. Xylene
• B. Ethanol
• C. Water
• D. Acetone

Answer: (A)

Clearing agents must dissolve the alcohol removed during dehydration and be miscible with paraffin to allow final infiltration. Aromatic hydrocarbons fit this role well because they dissolve lipids effectively and have a refractive index similar to paraffin, helping tissue become transparent for embedding. Xylene is a classic aromatic hydrocarbon used as a clearing agent for this reason. The other substances shown are not aromatic hydrocarbons and do not serve as standard clearing agents in routine processing: ethanol is an alcohol used for dehydration, water is not a solvent for clearing, and acetone is a ketone solvent not typically used as the clearing agent in standard workflows.