Sterilization Methods Flashcards

Which sterilization parameter is measured by a Biological Indicator (BI) containing Geobacillus stearothermophilus spores?

Answer: Steam sterilization efficacy

G. stearothermophilus spores are the standard BI for steam (autoclave) sterilization validation.

What is the primary mechanism by which gamma radiation achieves sterilization?

Answer: DNA strand breaks and free radical generation

Gamma radiation kills microorganisms by inducing DNA damage through direct ionization and reactive free radicals.

A tissue bank uses electron beam (e-beam) sterilization. Which feature distinguishes e-beam from gamma radiation?

Answer: Much faster processing time

E-beam processing is significantly faster than gamma because it uses accelerated electrons rather than isotope decay.

During ETO sterilization, which post-processing step is mandatory before tissue release?

Answer: Aeration to remove ETO residuals

Aeration is required after ETO sterilization to reduce toxic residual ethylene oxide to safe levels.

A Sterility Assurance Level (SAL) of 10⁻⁶ means:

Answer: One in a million units may harbor a viable microorganism

SAL 10⁻⁶ means there is no more than a 1-in-1,000,000 probability that a single viable microorganism remains on a sterilized item.

Which tissue type is MOST sensitive to gamma radiation-induced collagen degradation?

Answer: Soft tissue tendons and ligaments

Soft tissue grafts like tendons and ligaments are particularly vulnerable to radiation-induced collagen cross-linking and structural weakening.

What is the purpose of a dose-mapping study in radiation sterilization?

Answer: To identify minimum and maximum dose points within a product load

Dose mapping identifies the minimum and maximum radiation dose locations within the product configuration to ensure the entire load receives a sterilizing dose.