CTBS Storage and Distribution 3 — Questions and Answers
Question 1: When shipping fresh (non-frozen) cardiovascular tissue, the storage medium temperature must be maintained at:
- 4°C ± 2°C (Correct answer)
- -20°C ± 5°C
- 22°C ± 2°C
- 37°C ± 1°C
Correct answer: 4°C ± 2°C
Fresh cardiovascular tissue is stored and shipped at refrigerated temperatures of 4°C ± 2°C to maintain viability while inhibiting microbial growth.
Question 2: A tissue bank's distribution SOP requires two-person verification before releasing tissue. If only one person is available, the CORRECT action is to:
- Release the tissue with a single signature and document the reason
- Hold the release until a second qualified person is available (Correct answer)
- Ask a non-qualified employee to serve as the second verifier
- Skip verification and note it in the lot record
Correct answer: Hold the release until a second qualified person is available
SOPs requiring two-person verification are critical controls; deviation requires holding the release until proper verification can occur.
Question 3: The AATB standard requires that skin allografts stored in glycerol be maintained at a temperature of:
- -196°C
- -80°C
- 2–8°C (Correct answer)
- Room temperature (15–25°C)
Correct answer: 2–8°C
Glycerolized skin is stored at refrigerated temperatures of 2–8°C, as glycerol acts as a preservative that does not require freezing.
Question 4: What is the key reason tissue banks assign unique lot or unit numbers to each allograft?
- To meet insurance billing requirements
- To enable traceability from donor to recipient and support recalls (Correct answer)
- To simplify inventory counting
- To comply with hospital credentialing standards
Correct answer: To enable traceability from donor to recipient and support recalls
Unique identifiers are essential for donor-to-recipient traceability and enable targeted, efficient recalls when safety concerns arise.
Question 5: Which of the following storage containers is MOST appropriate for long-term cryogenic preservation of tissue at -196°C?
- Ultra-low freezer (-80°C)
- Mechanical freezer (-40°C)
- Liquid nitrogen Dewar (Correct answer)
- Refrigerated incubator (4°C)
Correct answer: Liquid nitrogen Dewar
Liquid nitrogen Dewars maintain temperatures at -196°C required for cryogenic storage of certain allografts such as bone marrow and some vascular grafts.
Question 6: If a hospital returns unused tissue to the tissue bank, what is the FIRST step the bank must take?
- Immediately restock the tissue for redistribution
- Quarantine and inspect the tissue per SOP before any reuse (Correct answer)
- Discard the tissue without inspection
- Issue a new Certificate of Analysis
Correct answer: Quarantine and inspect the tissue per SOP before any reuse
Returned tissue must be quarantined and evaluated against return acceptance criteria before it can be considered for redistribution.
Question 7: Under AATB standards, a tissue bank's storage area temperature monitoring system must have alarms that notify staff when:
- Temperatures exceed normal operating range (Correct answer)
- A power outage occurs anywhere in the building
- Humidity exceeds 80%
- Inventory drops below minimum stock levels
Correct answer: Temperatures exceed normal operating range
Alarm systems must be set to alert staff when storage temperatures deviate outside the validated operating range to enable timely corrective action.
CTBS Storage and Distribution 3
When shipping fresh (non-frozen) cardiovascular tissue, the storage medium temperature must be maintained at: