Specimens embedded in paraffin are floated on a warm water bath.

• A. Paraffin
• B. Resin
• C. Glycerin
• D. Gelatin

Answer: (A)

Paraffin wax is the embedding medium used in routine histology, and its properties explain why sections are floated on a warm water bath. After cutting, the paraffin sections are placed on a warm water bath so the wax softens just enough to relax the tissue and spread the section flat. The warmth helps remove wrinkles and folds, allowing the ribbon to lie smoothly on the slide for uniform mounting, staining, and examination. Resin blocks are much harder and are used for different applications (often electron microscopy), while glycerin or gelatin aren’t the standard embedding medium for this flotation step, so they aren’t used in this context.