This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
Tyndallisation is a method of - 
Select and explain. 
A. Growing bac teria in pure culture, B. Sterilization, C. Inoculation of media, D. Preserving cultures
B: Sterilization
Answer: B: Sterilization 
Explanation: A single exposure of 90 minutes usually ensures sterilization but for media containing sugars or gelatin, an exposure of 100-degree Celsius for 20 minutes on 3 successive days is used. This is known as tyndallisation or intermittent sterilization REF:Ananthanarayan and Panicker's Textbook ofMicrobiology 8thEdition pg no:32