title: Combined negative and positive selection of mobilized CD34 blood cells.
abstract: We tested four negative and two positive selection methods for separation of CD34+ cells from mobilized blood cells, and analysed fold-enrichment, purity and recovery of CD34+ cells after selection procedures. The elimination of mature CD34- cells was achieved by adhesion to nylon-wool fibre (5.9 +/- 1.0 mean fold-enrichment and 65.2 +/- 2.3 mean recovery of CD34+ cells). Standard or modified Ficoll-Hypaque and Percoll density gradients, as well as phagocytosis with magnetic beads, were less effective in eliminating CD34- cells, both purity and fold-enrichment of CD34+ cells being lower than those obtained with separation by nylon-wool. Both positive selection methods tested. Ceprate and MiniMacs System, generated highly purified CD34+ cell populations ranging from 80% to 90%. The recovery of CD34+ cells was optimal with MiniMacs (77.9 +/- 3.6) and low with Ceprate (28.8 +/- 2.8). Based on these results, in two large-scale experiments we combined nylon-wool fibre and MiniMacs System in a two-step separation procedure obtaining a 36.9 +/- 2.6 mean fold-enrichment and a 50.5 +/- 0.3 mean recovery of CD34+ cells. In this way we achieved optimal enrichment and recovery of CD34+ cells, with a substantial saving of cost compared to either selection method alone.
authors.affiliation: Division of Medical Oncology, Cristina Gandini Transplantation Unit, Istituto Nazionale Tumori, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Nicola
authors.forename: M
authors.initials: M
authors.lastname: Bregni
authors.forename: S
authors.initials: S
authors.lastname: Siena
authors.forename: P A
authors.initials: PA
authors.lastname: Ruffini
authors.forename: M
authors.initials: M
authors.lastname: Milanesi
authors.forename: F
authors.initials: F
authors.lastname: Ravagnani
authors.forename: A M
authors.initials: AM
authors.lastname: Gianni
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D002469:Cell Separation / Q000379:methods*; D002498:Centrifugation; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006801:Humans; D007937:Leukapheresis; D007962:Leukocytes / Q000378:metabolism*; D008280:Magnetics; D010587:Phagocytosis
chemical_list: D018952:Antigens, CD34