Abstract

As CB banks (CBB) become commonplace and seek to increase the numbers and diversity of their inventory, samples are being collected from off-site hospitals and shipped to the processing facility. CBB are concerned as to which variables may significantly influence the collection and banking of CB for future use in transplantation and regenerative medicine. Many CB samples are transported via airlines and questions have arisen as to whether samples may be negatively impacted by ionizing radiation encountered during transport or during airport security screening measures. Samples may arrive and be processed at different times during the work day, and concerns arise as to the effects of such delays in cryopreservation. Further, although many CBB store processed samples in multiple aliquots, the numbers of such aliquots are generally limited; raising the possibility that repeated rounds of freezing/thawing may be required for optimal use; which could affect sample utility. Analyses were performed to ascertain any effects of low dose radiation on CB utility, any changes in CB stem cells as a result of delays in cryopreservation, and to what end a CB sample could be frozen, thawed and refrozen before losing utility. It was observed that CB samples are able to tolerate normal delays and potential radiation exposures that might be routinely encountered during shipment to CBB. However, CB are only able to undergo limited rounds of freezing and thawing while maintaining stem/progenitor cell activity.