Among the listed equipment, which is designed to maintain samples at the lowest temperatures for microtomy?

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

Answer: (A)

For cutting frozen tissue, keeping the specimen at freezing temperatures during sectioning is essential to preserve morphology and prevent thawing artifacts. A cryostat combines a microtome with a cooling chamber, maintaining the sample and knife at roughly -20 to -30°C. This enables you to produce thin, intact frozen sections for rapid diagnostic evaluation. The other devices operate at higher temperatures or serve different purposes: a refrigerator stores samples at about 2–8°C, not freezing; an incubator creates warm conditions for cell culture; a flotation bath uses warm water to help flatten and mount sections, not to freeze tissue. So, the cryostat is specifically designed to hold the lowest temperatures needed for microtomy.