Most effective method of sterilization by heat is: (A) Hot air, (B) Boiling, (C) Steam, (D) Steam under pressure
Answer is D. Most effective method of sterilization by heat is by using moist heat (steam) above atmospheric pressure Autoclave is a classical example. Principle of autoclave- when water boils under pressure, instead of boiling at 100 degrees, it boils at a higher temperature. Hence the steam generated is at higher temperature.