Cord Blood Banking 4 — Questions and Answers
Question 1: Which cryoprotectant is most commonly used to preserve cord blood stem cells during cryogenic storage?
- Ethylene glycol
- Dimethyl sulfoxide (DMSO) (Correct answer)
- Glycerol
- Propylene glycol
Correct answer: Dimethyl sulfoxide (DMSO)
DMSO is the standard cryoprotectant used in cord blood banking because it penetrates cells and prevents ice crystal formation during freezing.
Question 2: In cord blood banking, what does 'CD34+ cell count' measure?
- The number of red blood cells removed during processing
- The concentration of hematopoietic stem and progenitor cells (Correct answer)
- The level of infectious disease markers
- The unit's HLA match score
Correct answer: The concentration of hematopoietic stem and progenitor cells
CD34 is a surface marker on hematopoietic stem and progenitor cells; its count is a key quality metric reported on every banked unit.
Question 3: Which storage temperature must cord blood units be maintained at in cryogenic tanks?
- -4°C (standard freezer)
- -20°C (deep freezer)
- -80°C (ultra-low freezer)
- -196°C (liquid nitrogen) (Correct answer)
Correct answer: -196°C (liquid nitrogen)
Cord blood is stored in liquid nitrogen at -196°C, which halts all biological activity and allows indefinite long-term preservation.
Question 4: A family relocating internationally wants to transfer their privately banked cord blood unit abroad. Which challenge is most likely?
- Units cannot legally leave the state of collection
- International transport requires specialized cryogenic shipping and import permits (Correct answer)
- The FDA must retest the unit before export
- Public banks must approve all international transfers
Correct answer: International transport requires specialized cryogenic shipping and import permits
International transfer requires validated cryogenic dry-shipper transport and compliance with both US export and destination country import regulations.
Question 5: What is the purpose of maternal blood testing at the time of cord blood collection?
- To determine the baby's blood type
- To screen for infectious diseases that could contaminate the cord blood unit (Correct answer)
- To measure the volume of cord blood collected
- To confirm gestational age
Correct answer: To screen for infectious diseases that could contaminate the cord blood unit
Maternal blood is tested for infectious diseases such as HIV, hepatitis B/C, and syphilis, as these pathogens can be transmitted to the cord blood unit.
Question 6: Which cord blood banking scenario qualifies for free public banking in most US states?
- All births at AABB-accredited hospitals
- Voluntary donation of the unit with no reserved family access (Correct answer)
- Families with documented financial hardship
- Births occurring after 38 weeks gestation only
Correct answer: Voluntary donation of the unit with no reserved family access
Public banking is free because families donate the unit without retaining exclusive rights; the bank lists it for any matching patient in need.
Question 7: A cord blood unit fails bacterial sterility testing after processing. The bank should:
- Release it only for autologous use
- Quarantine and destroy the unit per regulatory protocol (Correct answer)
- Reprocess the unit to eliminate contamination
- Store it separately and retest after six months
Correct answer: Quarantine and destroy the unit per regulatory protocol
A unit that fails sterility testing must be quarantined and discarded according to FDA regulations, as contaminated units pose serious infection risk to immunocompromised recipients.
Cord Blood Banking 4
Which cryoprotectant is most commonly used to preserve cord blood stem cells during cryogenic storage?