CTBS Sterilization Methods 2

Question 1

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

Accepted Answer

Steam sterilization efficacy

Answer

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

Question 2

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

Accepted Answer

DNA strand breaks and free radical generation

Answer

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

Question 3

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

Accepted Answer

Much faster processing time

Answer

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

Question 4

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

Accepted Answer

Aeration to remove ETO residuals

Answer

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

Question 5

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

Accepted Answer

One in a million units may harbor a viable microorganism

Answer

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.

(CTBS) Certified Tissue Bank Specialist Practice Test