The number of hematopoietic stem cells (HSCs) collected in cord blood (CB) at the birth of a baby is a limiting factor for efficacious use of CB in hematopoietic cell transplantation (HCT). We now demonstrate that collecting and processing of human CB at 4°C within minutes of the baby's birth results in significantly enhanced numbers of rigorously defined phenotypic HSC and self-renewing NSG immune-deficient mouse engrafting and SCID-repopulating cells. This was associated with decreased numbers of hematopoietic progenitor cells (HPC), as noted previously for hypoxia collected/processed cells blocking ambient air induced differentiation of HSC to HPC. We have thus defined a simple, cost-effective, means to collect increased numbers of CB HSC, of potential use for clinical CB HCT.

The number of collected cord blood (CB) hematopoietic stem cells at the birth of a baby is a limiting factor in use of CB for hematopoietic cell transplantation. This study now demonstrates, by collecting and processing CB at 4°C, that significantly enhanced numbers of CB hematopoietic stem cells can be attained for potential use in clinical CB hematopoietic cell transplantation, in a simple and cost-effective manner.