Microbiology · General Microbiology (Bacterial Genetics, Culture Media, Stains, Sterilization)

Heat-sensitive plastic endotracheal tubes must be sterilized without leaving toxic residues. Which agent is most appropriate among the following?

  • A Autoclave at 121 degrees Celsius
  • B Hot air oven at 160 degrees Celsius
  • C Ethylene oxide gas followed by adequate aeration
  • D Boiling at 100 degrees Celsius for 30 minutes
Correct answer: C. Ethylene oxide gas followed by adequate aeration

Explanation

Ethylene oxide is a gaseous alkylating agent effective at low temperature, so it suits heat- and moisture-labile items such as plastic tubing. Because both the gas and its breakdown products are toxic, items require prolonged aeration before use. Autoclave and hot air oven would melt or deform the plastic, and boiling fails to kill spores.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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