CTBS Sterilization Methods 3

Question 1

Which ISO standard specifically governs the development and validation of sterilization processes for medical devices and tissues?

Accepted Answer

ISO 11135 / ISO 11137

Answer

ISO 11135 covers ETO sterilization and ISO 11137 covers radiation sterilization validation for medical devices and tissue products.

Question 2

A tissue bank is validating a new VHP (vaporized hydrogen peroxide) sterilization cycle. Which BI organism is most appropriate?

Accepted Answer

Geobacillus stearothermophilus

Answer

G. stearothermophilus is also used as the BI for VHP sterilization validation due to its high resistance to oxidizing agents.

Question 3

When processing cortical bone with low-dose radiation, what adjunct method is often combined to achieve adequate sterility?

Accepted Answer

Aseptic processing techniques

Answer

Low-dose radiation is often combined with rigorous aseptic processing to achieve the required SAL while minimizing tissue damage.

Question 4

The D-value in sterilization science refers to:

Accepted Answer

The time or dose required to reduce the microbial population by 90% (1 log)

Answer

The D-value (decimal reduction value) is the time or dose needed to reduce the viable microbial population by one log (90%).

Question 5

Which property of ethylene oxide makes it effective as a sterilant at low temperatures?

Accepted Answer

It alkylates proteins and nucleic acids, disrupting cellular function

Answer

ETO is an alkylating agent that chemically modifies proteins and nucleic acids, rendering microorganisms non-viable without requiring high heat.

(CTBS) Certified Tissue Bank Specialist Practice Test