What is sterilisation?

• A. The complete destruction of bacteria, spores and viruses
• B. Killing surface bacteria
• C. Cleaning equipment
• D. Reducing microbial load to safe levels

Answer: (A)

Sterilisation means removing or destroying all viable microorganisms on an object or in a substance, including bacteria, spores, and viruses. This level of clean is why it’s essential for items used in invasive procedures or critical environments, where even a single spores or virus could pose a risk. The choice that states complete destruction aligns with this definition, capturing the idea that sterilisation achieves no remaining life — not just reducing numbers.

Killing surface bacteria describes disinfection, which reduces or eliminates harmful microbes on surfaces but may not affect all spores or all microbes. Cleaning removes dirt and debris but does not guarantee microbial destruction. Reducing microbial load to safe levels is sanitisation or disinfection, not sterilisation. Methods like autoclaving, certain chemical sterilants, or irradiation are used to achieve true sterility.