Sections 90 nm thick are commonly cut with which instrument?

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

Answer: (C)

Ultrathin sectioning for electron microscopy requires an instrument capable of producing extremely thin slices, around 60–100 nanometers. An ultramicrotome is specifically designed for this purpose, usually cutting resin-embedded tissue with a diamond knife to achieve the necessary ultrathin sections for TEM.

Rotary microtomes cut paraffin-embedded tissue in the micrometer range (about 3–5 µm) for light microscopy. Cryostats produce frozen sections for rapid diagnostic slides, typically a few micrometers thick. Vibratomes cut thicker, fresh tissue slices (tens to hundreds of micrometers) for applications like physiology or culture. Therefore, 90 nm sections are best produced with an ultramicrotome.