Which of the following items is suitable for sterilization by dry heat (hot air oven)? (Select the material that tolerates high temperature without moisture.)
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AIntravenous (IV) solution
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BPlastic IV bags
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CGlass pipettes
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Drubber gloves
Answer
Correct Answer: Glass pipettes
Explanation
Introduction: Dry heat sterilization (e.g., 160–170 °C for 2 hours) is ideal for moisture-sensitive, heat-stable items such as glassware and metal instruments. This question asks you to pick the appropriate item.
Given Data / Assumptions:
- Dry heat destroys by oxidative processes and requires higher temperatures and longer times than steam.
- Liquids and many plastics are unsuitable for dry heat.
- Glass tolerates high temperatures without deformation.
Concept / Approach: Match the sterilization method to material tolerance. Glass pipettes withstand hot air oven temperatures, achieving sterility without moisture. Fluids and many polymers are better processed by moist heat or low-temperature gas methods.
Step-by-Step Solution: Eliminate liquids (IV solution) that would evaporate/overheat in dry heat. Eliminate heat-sensitive plastics and rubber (IV bags, gloves). Identify glass pipettes as hot-air-compatible. Select “Glass pipettes.”
Verification / Alternative check: Lab SOPs routinely sterilize glassware by hot air ovens; liquids are autoclaved by moist heat instead.
Why Other Options Are Wrong:
- IV solution / Plastic IV bags: Use moist heat or aseptic manufacture; dry heat is unsuitable.
- Rubber gloves: Typically sterilized by EtO or gamma; dry heat degrades elastomers.
Common Pitfalls: Assuming any heat method works for all items; material compatibility is crucial.
Final Answer: Glass pipettes are appropriate for dry heat sterilization.