Mobilized Leukopak (Dual). CD34+ stem cells are multipotent and can give rise to all cell types in blood. CD34 cells are most known for its expression on hematopoietic progenitor cells found in bone marrow and cord blood. Donors are injected with a combination of Plerixafor and G-CSF, which stimulates the bone marrow to produce a large number of hematopoietic and progenitor stem cells and mobilizes them into the peripheral blood stream. CD34+ cells are isolated using positive immunomagnetic cell separation procedures from a mobilized leukapheresis collection.