title: Relative sedimentation of hematopoietic progenitors in human cord blood, peripheral blood, and bone marrow as determined by counterflow centrifugal elutriation.
abstract: BACKGROUND
  The current use of cord blood (CB) and peripheral blood (PB) stem cells as alternatives or adjunctives to bone marrow (BM) for hematopoietic reconstitution in the treatment of various diseases prompted an examination of the progenitors of these tissues by counterflow centrifugal elutriation (CCE).
  
  
  METHODS
  The cells, obtained from normal donors not primed with colony-stimulating factors, were centrifuged at 3000 rpm in a Beckman Sanderson Chamber. Fractions (Frs.) were collected at (1) 18 ml/min, (2) 25 ml/min, (3) 32 ml/min, (4) 40 ml/min, and (5) the rotor-off fraction.
  
  
  RESULTS
  Clonogenic assays revealed differences in the fraction localizations for CB and PB when compared to BM, i.e., recovery of the colony-forming units for CB and PB was greater in the small-medium cell size CCE fractions, and those from BM were found primarily among the medium-large cell size fractions. Thus, although colony-forming unit granulocyte/macrophage colonies were distributed throughout Frs. 2-5 of BM, CB and PB showed 80% of the total to be in Frs. 2 and 3. Further, although burst-forming unit erythroid colonies of BM were distributed equally in Frs. 2 and 3, greater than 70% of the total burst-forming unit erythroid colonies in CB and PB were found in Fr. 2. Distribution of the CD34 cells in the fractions correlated with the colony-forming units in that these were found primarily in Frs. 2 and 3 of CB and PB, whereas they were present in significant numbers throughout Frs. 1-5 of BM.
  
  
  CONCLUSIONS
  We interpret these findings to indicate CB and PB to be qualitatively similar in their hematopoietic lineage development and to contain a greater proportion of early versus late progenitors relative to those found in BM.
authors.affiliation: Department of Pediatrics, University of Tennessee Graduate School of Medicine, The Thompson Cancer Survival Center, Knoxville 37916, USA.
authors.forename: N
authors.initials: N
authors.lastname: Gengozian
authors.forename: R J
authors.initials: RJ
authors.lastname: Hill
authors.forename: M R
authors.initials: MR
authors.lastname: Caudle
authors.forename: T J
authors.initials: TJ
authors.lastname: Panella
mesh_terms: D001773:Blood Cells / Q000166:cytology*; D001799:Blood Sedimentation; D001854:Bone Marrow Cells / Q000166:cytology*; D002498:Centrifugation / Q000379:methods; D003114:Colony-Forming Units Assay; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans