Tissues embedded in glycol methacrylate are commonly cut with which microtome?

• A. Cryostat
• B. Rotary microtome
• C. Ultramicrotome
• D. Vibratome

Answer: (B)

Glycol methacrylate makes a rigid, plastic-like block that is cut at room temperature, so a rotary microtome is the right tool. Its sharp blade and controlled advancing mechanism produce clean, uniform thin sections (often around 1–5 micrometers) from resin-embedded tissue, which is ideal for light microscopy with methacrylate blocks.

A cryostat would freeze tissue, which isn’t suitable for resin blocks and can create artifacts. An ultramicrotome is used for ultrathin sections (tens of nanometers) intended for electron microscopy, not the light-m microscope thicknesses typically needed with glycol methacrylate. A vibratome cuts thicker slices from unfixed or soft tissue, usually in a medium like agarose, not from hard resin blocks.