CTBS Processing Techniques 5

Question 1

Which of the following processing steps is specifically aimed at prion (TSE) risk reduction in neural tissue allografts?

Accepted Answer

Sodium hydroxide (NaOH) treatment combined with autoclaving at 134°C

Answer

Prions are highly resistant to standard sterilization; NaOH treatment (1N, 1 hour) combined with autoclaving at 134°C for at least 18 minutes is recommended by WHO for prion inactivation.

Question 2

In a tissue bank clean room, what is the distinction between 'controlled environment' and 'critical zone'?

Accepted Answer

Controlled environment is the overall clean room space; critical zone is where tissue is directly exposed to the environment

Answer

The controlled environment encompasses the entire clean room maintained at specified air quality standards, while the critical zone is the specific area of direct tissue exposure requiring the highest (ISO 5) air quality.

Question 3

What is the function of DMSO (dimethyl sulfoxide) when used in tissue cryopreservation?

Accepted Answer

It penetrates cell membranes to prevent intracellular ice crystal formation

Answer

DMSO is a cryoprotectant that rapidly penetrates cell membranes and reduces intracellular ice crystal formation during freezing, thereby preserving cell membrane integrity and viability.

Question 4

Which in-process test is used to confirm the effectiveness of the decontamination step during bone allograft processing?

Accepted Answer

Microbiological cultures (aerobic, anaerobic, and fungal) from process samples

Answer

Microbiological cultures testing for aerobic bacteria, anaerobic bacteria, and fungi from tissue samples taken after decontamination steps confirm the effectiveness of bioburden reduction.

Question 5

During the processing of pericardium allografts for cardiac surgery use, glutaraldehyde fixation is sometimes applied. What is the primary effect of this fixation?

Accepted Answer

It crosslinks collagen to reduce immunogenicity and improve durability, but eliminates cell viability

Answer

Glutaraldehyde crosslinks collagen in pericardium, masking antigenic epitopes to reduce immune response and increasing structural durability, but the resulting tissue is acellular and not viable.

(CTBS) Certified Tissue Bank Specialist Practice Test

(CTBS) Certified Tissue Bank Specialist Practice Test

CTBS Processing Techniques 5