A cryostat is typically maintained at which temperature?

• A. 0 C
• B. -20 C
• C. 4 C
• D. -80 C

Answer: (B)

The main idea is that a cryostat must keep tissue frozen enough to cut into thin sections. Maintaining the chamber around minus twenty Celsius freezes the tissue sufficiently so the microtome can slice cleanly without it becoming pliable or smeared. This temperature balances rigidity and handleability, reducing ice crystal damage that can distort tissue morphology. If you set the temperature near freezing (0 C) or slightly above (4 C), the tissue won’t be frozen well enough for accurate sectioning. Going much colder, like minus eighty, would make the tissue too brittle and harder to section, and is generally used for storage, not routine cutting. So minus twenty Celsius is the standard, best-fit setting for cryostat sectioning.