CTBS Sterilization Methods 4

Question 1

Which radiation dose range is typically used by tissue banks for terminal sterilization of allografts to achieve SAL 10⁻⁶?

Accepted Answer

15–25 kGy

Answer

Most tissue banks use doses between 15 and 25 kGy for terminal sterilization, balancing sterility assurance with tissue integrity.

Question 2

During ETO sterilization, relative humidity inside the chamber is critical because:

Accepted Answer

Moisture hydrates spore coat, enabling ETO penetration

Answer

Adequate moisture (30–80% RH) is needed to hydrate the spore coat, allowing ETO to penetrate and alkylate cellular components effectively.

Question 3

A tissue bank switches its radiation sterilization source from Co-60 to e-beam. Which limitation of e-beam must be addressed?

Accepted Answer

Limited penetration depth for dense or thick products

Answer

E-beam electrons have limited penetration compared to gamma photons, restricting its use to thinner or lower-density tissue configurations.

Question 4

Which chemical parameter is MOST critical to monitor and control during an ETO sterilization cycle?

Accepted Answer

ETO gas concentration, temperature, humidity, and time

Answer

ETO efficacy depends on the precise control of gas concentration, temperature, humidity, and exposure time — all four must be within validated ranges.

Question 5

What does the term 'bioburden' mean in the context of tissue sterilization?

Accepted Answer

The total number of viable microorganisms present on a product before sterilization

Answer

Bioburden is the total count of viable microorganisms on or in a product before terminal sterilization, used to calculate the required sterilization dose.

(CTBS) Certified Tissue Bank Specialist Practice Test

(CTBS) Certified Tissue Bank Specialist Practice Test

CTBS Sterilization Methods 4