Isolation of Human CD34+ Peripheral Blood Stem Cells Using an Immunomagnetic Positive Selection System: Prior Monocyte Depletion Using a Nylon-Wool Column

An immunomagnetic separation system has been used to collect CD34+ cells in mobilized blood after treatment with a nylon-wool column. Cell purities were increased from 2.6% preseparation to 94.6% postseparation, with a mean yield 45.2% (n = 4). Forty percent of CD34+ cells separated by the immunomagnetic procedure formed colonies in the presence of hematopoietic growth factors in a limiting dilution assay. Eleven percent of these clones proliferated to over 105 cells and contained megakaryocytes.