How is an inoculating loop or needle sterilized prior to use?
Correct Answer:
holding in the hottest part of the Bunsen burner flame until red-hot
Rationale:
✨ Holding in the hottest part of the Bunsen burner flame until red-hot — This is correct because direct flaming incinerates all microorganisms, ensuring the inoculating loop or needle is sterile before and after use—
✨ Exposure to UV radiation for 15 seconds — This is incorrect because UV light is not reliable for sterilizing small metal instruments; it is used for surface disinfection, not tools—
✨ Soaking in 95% ethyl alcohol for several minutes and allowing to air dry — This is incorrect because alcohol is a disinfectant, not a sterilant; spores and some microbes can survive—
✨ Dipping into a beaker of boiling water — This is incorrect because boiling reduces microbial load but does not guarantee sterilization, especially against spores—
