The dehydration and clearing steps can be omitted when using which material?

• A. Water soluble wax
• B. Paraffin
• C. Resin
• D. Gelatin

Answer: (A)

Dehydration and clearing are used to remove water from tissue and replace it with a solvent compatible with the embedding medium. When the embedding medium is water-soluble, the tissue can be infiltrated directly from an aqueous environment, so those steps aren’t needed. Water-soluble wax is designed for this, allowing infiltration from water without first drying and clearing. In contrast, paraffin and resins are hydrophobic and require water removal and solvent exchange before infiltration, so dehydration and clearing remain essential. Gelatin isn’t used as a standard hydrophobic embedding medium for routine paraffin processing, so it doesn’t offer the same ability to skip these steps.