Which of the following methods would be best for sterilizing a sample of a heat-sensitive solution?

• A. Autoclaving
• B. Filtration
• C. Boiling
• D. Dry heat oven

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the nature of the sample. Since the solution is heat-sensitive, it means that high temperatures could denature or degrade the components in the solution.
2. Step 2: Review the sterilization methods: Autoclaving uses high-pressure saturated steam at around 121°C, which is effective but involves high heat; Boiling involves heating at 100°C, which can damage heat-sensitive materials; Dry heat oven sterilization uses hot air at even higher temperatures for longer times, also unsuitable for heat-sensitive solutions.
3. Step 3: Consider filtration as a sterilization method. Filtration involves passing the solution through a membrane filter with pores small enough (usually 0.22 micrometers) to remove bacteria and other microorganisms without applying heat.
4. Step 4: Recognize that filtration is ideal for sterilizing heat-sensitive solutions because it avoids heat exposure while effectively removing microbial contaminants.
5. Step 5: Conclude that among the given options, filtration is the best method for sterilizing a heat-sensitive solution.