Question

Animal cell lines are typically preserved long-term in liquid nitrogen at

• A. \(0^\circ\mathrm{C}\)
• B. \(-20^\circ\mathrm{C}\)
• C. \(-80^\circ\mathrm{C}\)
• D. \(-196^\circ\mathrm{C}\)

Hint:

Cryopreservation conditions: \[ \boxed{ \text{Liquid nitrogen} = -196^\circ\mathrm{C} } \] Cryoprotectants such as DMSO are commonly added to prevent ice crystal damage.

Answer 1

The Correct Option is D

Step 1: Recall the method of cryopreservation. Long-term preservation of animal cell lines is achieved by cryopreservation in liquid nitrogen.

Step 2: Identify the storage temperature. Liquid nitrogen has a temperature of \[ \boxed{-196^\circ\mathrm{C}.} \] At this temperature, cellular metabolism is effectively halted, allowing long-term storage. Therefore, \[ \boxed{(D)} \] is the correct answer.