In the process of freeze drying, a dense cell suspension is placed in small vials and is frozen at

Q. In the process of freeze drying, a dense cell suspension is placed in small vials and is frozen at

1. -60 to -78°C
2. -20 to -30°C
3. -30 to -48°C
4. -48 to -58°C

Answer: -60 to -78°C