Which device is used to cut tissue sections at very low temperatures?

• A. Cryostat
• B. Refrigerator
• C. Incubator
• D. Flotation bath

Answer: (A)

Cutting tissue sections at very low temperatures requires a refrigerated microtome housed in a cold chamber—the cryostat. The tissue is frozen quickly and kept rigid, allowing the knife to slice very thin sections (often a few microns) without tearing or smearing. This rapid freezing and temperature control preserve cellular details and enable fast preparation of frozen sections, which is essential for intraoperative diagnoses or urgent assessments.

The other devices aren’t used for cutting frozen tissue: a refrigerator mainly stores specimens at cool temperatures but isn’t designed for sectioning; an incubator maintains warm conditions for cell culture or reactions; a flotation bath is used to float and handle sections during mounting or staining, not to cut tissue.