The image shown depicts a piece of sterilization equipment. Which of the following statements regarding its sterilization properties is INCORRECT?

Appeared in: INI-CET EXAM -2026

Explanation

The statement is incorrect because prions are infectious protein particles that are exceptionally resistant to conventional sterilization methods.
A standard autoclave cycle of 121°C for 15 minutes is effective for destroying bacteria, viruses, and even highly resistant bacterial spores, but it is insufficient to reliably inactivate prions.
Prion decontamination requires more aggressive methods, such as autoclaving at a higher temperature of 134°C for an extended duration (at least 18 to 60 minutes), often combined with chemical pre-treatment.

Option A: This is a correct statement. Autoclaves are a form of moist heat sterilization that operate under pressure to achieve temperatures above the normal boiling point of water (100°C).
Option B: This is a correct statement related to autoclave quality assurance. The Bowie-Dick test is used for pre-vacuum autoclaves to ensure proper air removal for effective steam penetration. A successful test confirms the machine is working correctly.
Option D: This is a correct statement. Autoclaving is the standard and most widely used method for sterilizing heat-stable items in laboratories and healthcare settings, including culture media.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Principles of autoclaving and microbial resistance to sterilization as background academic context rather than a clinical decision trigger.
Understanding the extreme resistance of prions is critical in clinical practice to prevent the iatrogenic (healthcare-associated) transmission of fatal neurodegenerative diseases like Creutzfeldt-Jakob Disease (CJD).
Surgical instruments used on patients with known or suspected CJD must undergo specific, stringent 'prion protocols' for decontamination. Relying on standard sterilization creates a significant patient safety risk.
What if the question was about bacterial spores? If a statement read 'Bacterial spores are not destroyed at 121°C for 15 minutes,' it would be incorrect. This cycle is specifically validated using biological indicators containing highly resistant spores (e.g., Geobacillus stearothermophilus) to confirm lethality.

How to Approach the Question

First, identify the equipment in the image as an autoclave, a device used for steam sterilization.
Carefully read the question and note the keyword 'INCORRECT'. Your goal is to find the false statement among the options.
Evaluate each option based on established principles of microbiology and sterilization.
Analyze Option A: Recall that autoclaves use steam under pressure to exceed 100°C. This is a fundamental and true principle.
Analyze Option B: Recall that the Bowie-Dick test is a standard quality control test for certain autoclaves. A successful test indicates proper function. This is a true statement.
Analyze Option D: Recall that sterilizing culture media is a very common and appropriate use for an autoclave. This is a true statement.

Concept Tested & Keywords

Concept Tested: Principles of autoclaving and microbial resistance to sterilization.
Stem keywords: sterilization equipment, autoclave, sterilization properties
Lead-in keywords: INCORRECT
Negative lead-in flag: The question asks for the INCORRECT statement.

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 127-129

E6 Microbiology OneStop Sastry p. 50-52

Practise the full INI-CET EXAM -2026

Attempt every question from this paper in a timed mock, then review the full solution for each one.