title: Factors affecting banking quality of umbilical cord blood for transplantation.
abstract: BACKGROUND
  The most important objective for cord blood banks is to store cord blood units of high quality, which is determined by total nucleated cells (TNCs) and CD34+ cells. Determining the factors affecting the stored life-saving cells would be beneficial to the field.
  
  
  METHODS
  A total of 4930 cord blood units were collected between January 2007 and October 2009 and processed using a double extraction technique to sediment red blood cells with variable centrifugation time determined by the formula CT = KL - M, where CT is centrifuge time, K is 7.7227, M is 29.742, and L is ln (volume of cord blood with anticoagulant). The recovery rate of TNCs and other relevant factors affecting banking quality were analyzed.
  
  
  RESULTS
  The mean recovery rate of TNCs was 97.7 ± 2.5% with 0.04% (2/4930) units below 80% and 10.8% (532/4930) units below 95%. The TNCs per unit was affected by gestation duration (p < 0.01), sex of infant (p < 0.01), mode of delivery (p < 0.01), collection method (p < 0.01), and ethnicity (p < 0.001). The number of postprocessing CD34+ cells was affected only by sex of the infant (p < 0.05). The viability of nucleated cells after processing was 94.8 ± 4.8% and was affected by the number of hours between collection and processing (p < 0.01). In contrast, the viability of CD34+ cells was 99.5 ± 1.0% (n = 30) when samples with low viability of TNCs were assessed. The results did not reveal a significant correlation (r = 0.07, p = 0.38).
  
  
  CONCLUSIONS
  The double extraction technique provides a high and consistent recovery of TNCs, which ensures that more life-saving cells will be banked for transplants.
authors: Progenics Cord Blood Cryobank, Toronto, Ontario, Canada. hyang@progenicscryobank.com
authors: Hongyou
authors: H
authors: Yang
authors: Mona R
authors: MR
authors: Loutfy
authors: Stephanie
authors: S
authors: Mayerhofer
authors: Paul
authors: P
authors: Shuen
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D001771:Blood Banks; D001772:Blood Cell Count; D001793:Blood Preservation / Q000379:methods*; D002467:Cell Nucleus; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival; D002498:Centrifugation; D036101:Cord Blood Stem Cell Transplantation / Q000592:standards*; D003430:Cross-Sectional Studies; D015925:Cryopreservation; D036861:Delivery, Obstetric / Q000379:methods; D005006:Ethnicity; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D005865:Gestational Age; D006412:Hematopoietic Stem Cells / Q000648:ultrastructure; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies
chemical_list: D018952:Antigens, CD34