Thawing stem cells

Cord blood (CB) is a rich source of hematopoietic stem cells and progenitors cells, and CB transplantation has been used to treat both malignant and non-malignant disorders. In the Early Edition of the Proceedings of the National Academy of Sciences, Hal Broxmeyer and colleagues report analysis of the efficiency of recovery of stem cells from CB after 15 years of cryopreservation (PNAS, DOI/10.1073/pnas.0237086100, December 30, 2002).

Extended freezing periods appeared to have no adverse effects on the recovery of progenitor populations or their renewal and proliferative capacities in culture. In addition, CD34⁺ cells isolated from CB were able to repopulate the hematopoietic system in vivo, when injected into sublethally irradiated non-obese diabetic (NOD)/severe combined immunodeficient (SCID) mice.