Chloroform is classified as which type of solvent in dehydration, clearing, or infiltration/embedding?

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

Answer: (B)

Chloroform is used as a clearing solvent in tissue processing. Clearing agents replace the dehydration medium (alcohol) and prepare the tissue for paraffin infiltration by being miscible with both alcohol and paraffin, which helps to match refractive indices and allow thorough infiltration. Because it doesn’t remove water from tissue, it isn’t a dehydrant, and it isn’t the embedding medium itself—paraffin is. There isn’t a universal solvent that handles both dehydration and clearing in a single step.