COMPARISON OF PURITY AND ENRICHMENT OF CD34(-MARROW, UMBILICAL-CORD AND PERIPHERAL-BLOOD (PRIMED FOR APHERESIS) USING 5 SEPARATION SYSTEMS() CELLS FROM BONE)

Interest in the isolation and characterization of primitive hemopoieti c cells in both the clinical and research fields has rapidly increased , In parallel, different purification systems have been developed to i solate these cells. We have compared five different methods for separa tion of CD34(+) cells from human umbilical cord blood, normal bone mar row and apheresis harvests and analyzed purity, recovery, yield and en richment of colony forming cells (CFC) for each individual system. Our results indicate that the most reliable methods of purification for a ll samples were fluorescence activated cell sorting (FACS) and magneti c activated cell sorting (MACS) which consistently yielded high puriti es (>70%) and enrichment of CFC. In this respect the enrichment of CFC from the MACS was superior to all the other systems including FAGS, S imilar results (>70%) for purity mere obtained using avidin affinity c olumns and a biotinylated antibody but neither yield nor CFC enrichmen t approached the values achieved with MACS. On average CFC enrichment using these affinity columns mas greater than that observed for FAGS w hile the purity mas comparable. Both CELLector flasks and immunomagnet ic beads coated with CD34 antibodies were less effective in our hands in separating purified populations of progenitor cells. Both purity an d CFC enrichment of CD34(+) cells using these methods were at least 50 % lower than obtained with either FACS, MACS or affinity columns.