Cellodin 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: (C)

The type of solvent used here is infiltration/embedding. In histology, after dehydration and clearing, the tissue needs to be impregnated with an embedding medium (like celloidin) so it can be supported for thin sectioning. A solvent such as Cellodin helps the embedding medium penetrate the tissue, preparing a solid block for microtomy. It isn’t used to remove water (that’s dehydration) and it isn’t used to clear (that’s clearing). The role is specifically to carry the embedding medium into the tissue, which is why it’s classified as an infiltration/embedding solvent.