¹Alberta Cord Blood Bank, Edmonton, Alberta, Canada

²Canadian Blood Services, Edmonton, Alberta, Canada

³Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada

⁴Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada

Correspondence to: Dr H Yang, Alberta Cord Blood Bank, 3rd Floor Canadian Blood Services Building, 8249-114 Street, Edmonton, Alberta T6G 2R8, Canada

Human umbilical cord blood (UCB) has been used successfully to treat a variety of genetic, hematological, and oncologic disorders. However, the low number of hematopoietic progenitor cells available in donated cord blood samples limits transplantation of cord blood to children and small adults. Reduction of the volume of umbilical cord blood is widely used in cord blood banking to reduce the storage requirements in large-scale UCB banks. Unfortunately, during the volume reduction process, up to 40% or more of the progenitor cells are lost using current reduction methods. This study describes a highly reproducible, double collection technique using Pentaspan to reduce UCB volume by red cell depletion. This results in the preservation of critical hematopoietic progenitor cells. The final volume of the leukocyte concentrates (LC) was 19.8 ± 0.4 ml with 95% red cell depletion. The recovery of nucleated cells (NC), mononuclear cells (MNC), CD34⁺ cells and colony-forming units (CFU) following double collection was 89%, 94%, 96%, and 106%, respectively. This is significantly higher than the recovery from single collections, where recovery was 74%, 77%, 84%, and 91% for NC, MNC, CD34⁺ and CFU, respectively. The double collection technique provides an efficient and highly reproducible method for the preparation of UCB for long-term storage and transplantation. Bone Marrow Transplantation (2001) 27, 457-461.

umbilical cord blood; flow cytometry; volume reduction; leukocytes; CD34⁺