Question Detail
Question
During lyophilisation of liquid culture of a microorganism, it is frozen with dry ice and exposed to vacuum for -------to remove all the water
Correct Answer
Option C is the correct answer.
Detailed Explanation
Lyophilization (freeze-drying) involves freezing the sample, then reducing the surrounding pressure to allow the frozen water to sublimate directly from solid ice to water vapor, bypassing the liquid phase. Dry ice is used for initial freezing, but sublimation is the water removal process.
Hint
What is the physical process by which a solid turns directly into a gas without becoming a liquid?