title: CD34-positive cell selection by immunomagnetic beads and chymopapain.
abstract: BACKGROUND
  Pluripotent hemopoietic stem cells, progenitors of all hemolymphopoietic lineages, and clonogenic cells from many patients with acute nonlymphocytic leukemia (ANLL) and chronic myeloid leukemia (CML) express the CD34 antigen on their surface. Isolation of these cell populations is of primary experimental and clinical importance.
  
  
  METHODS
  Six bone marrow (BM) and 10 peripheral blood (PB) samples were obtained from 2 normal individuals, 3 patients with CML and 9 with ANLL. The CD34+ cell fraction was isolated using MY10 antibody, sheep anti-mouse immunomagnetic beads and the enzyme chymopapain. Indirect immunofluorescence and semisolid culture were employed to evaluate the percentage of CD34+ cells and that of clonogenic cells in each cell fraction.
  
  
  RESULTS
  The frequency of CD34+ cells in the original unseparated populations was (mean +/- SE) 24.3 +/- 7.3%, and reached 85.0 +/- 2.7% in the isolated CD34-positive fractions; in the negative fractions it was only 2.7 +/- 1.7%. According to these results, the great majority of clonogenic cells was separated in the CD34-positive fractions and depleted in those CD34-negative. Moreover, chymopapain was shown to be non-toxic to the clonogenic cells.
  
  
  CONCLUSIONS
  Positive immunoselection using My10 Ab, immunomagnetic beads and chymopapain is a method for isolating almost pure progenitors from the BM and PB of normal individuals and patients with myeloid leukemias.
authors.affiliation: University of Cincinnati Medical Center, OH.
authors.forename: F
authors.initials: F
authors.lastname: Silvestri
authors.forename: S
authors.initials: S
authors.lastname: Banavali
authors.forename: M
authors.initials: M
authors.lastname: Yin
authors.forename: V
authors.initials: V
authors.lastname: Gopal
authors.forename: C
authors.initials: C
authors.lastname: Savignano
authors.forename: M
authors.initials: M
authors.lastname: Baccarani
authors.forename: H D
authors.initials: HD
authors.lastname: Preisler
mesh_terms: D015703:Antigens, CD; D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D001853:Bone Marrow / Q000473:pathology; D002469:Cell Separation / Q000379:methods*; D002917:Chymopapain; D005455:Fluorescent Antibody Technique; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D007163:Immunosorbent Techniques; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D015470:Leukemia, Myeloid, Acute / Q000473:pathology*; D008280:Magnetics; D008863:Microspheres; D014411:Neoplastic Stem Cells / Q000276:immunology
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002917:Chymopapain