Glycol methacrylate functions as which of the following?

• A. An infiltrating medium that is converted to a solid
• B. A fixative that cross-links proteins
• C. A clearing agent for lipids
• D. A dehydrating solvent

Answer: (A)

Glycol methacrylate acts as an embedding resin that infiltrates the tissue and then polymerizes to a solid block. This solid block can be sectioned into thin slices for microscopy, preserving cellular detail and morphology better in some cases than paraffin. It is not a fixative that cross-links proteins, not a clearing agent for lipids, and not a dehydrating solvent. The key idea is that it infiltrates the tissue and, after polymerization, becomes a solid medium that supports precise, high-quality sectioning.