Hematopoietic progenitors express high levels of the cell surface glycoprotein CD34. Cells are =90% CD34+. As these cells mature and differentiate, the levels of CD34 expression decrease. CD34+ cells are capable of initiating long-term hematopoiesis both in vitro and in vivo. CD34+ progenitors are available from Bone Marrow and Cord Blood. CD34+ progenitors are isolated from mononuclear cells using positive immunomagnetic selection. If you require a large number of donors for your study, we suggest that you purchase CD34+ cells from bone marrow.