For decades, medical professionals and researchers have relied on and even preferred stem cells derived from bone marrow for transplantation and research purposes. When bone marrow transplantation began in 1956, this was the only way to harness the body’s most versatile cells.

In the nearly 65 years since the first successful bone marrow transplant, there have been immense leaps forward in both stem cell sourcing processes and technologies. Today, mobilized CD34+ stem cells offer several advantages over stem cells derived from bone marrow and other sources.

A History of Stem Cell Sourcing

For decades after the 1950s, bone marrow was collected from the donor and transfused into the recipient, where the cells in the donor marrow naturally took up residency in the patient’s marrow, beginning the healing process. While the relative success increased over time, one roadblock remained: the intensive collection procedure.

To donate, bone marrow donors had to undergo multiple aspirations from the iliac crest of the pelvic bone via insertion of a cannula through the outer bone into the trabecular bone and the marrow. Ouch. The procedure is uncomfortable for some and painful for others, which was no doubt a deterrent from donating.

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Practices remained mostly the same until the late 1980s when scientists developed the ability to harness a high percentage of hematopoietic stem cells from umbilical cord blood. While cord blood stem cells are theoretically easier to collect, the volume of cells from each donation is limited and cannot replenish the bone marrow without further cell expansion.

Harnessing Stem Cells from Peripheral Blood

With the introduction of recombinant growth factors, scientists were able to collect stem cells directly from peripheral blood in the 1990s. An injection of granulocyte colony stimulating factor (G-CSF) increases production of granulocytes in the bone marrow. It also causes stem cells to migrate out of the marrow into circulation, where they can be collected by apheresis — a much less invasive procedure than bone marrow collection.

Mobilized CD34+ Stem Cells vs. Bone Marrow Stem Cells: Which is Best?

Comparisons between the standard bone marrow stem cells and the newer mobilized CD34+ stem cells were both inevitable and necessary. After much scrutiny and testing, it was determined that the two sources of stem cells were interchangeable. In fact, today’s bone marrow transplants are not actually bone marrow, but instead leukapheresis collections from donors who have received G-CSF.

These mobilized leukapheresis donations continue to be improved with the addition of Plerixafor (Mozibil), a CXCR4 inhibitor that also moves stem cells into the circulation. We offer mobilized leukopaks from both G-CSF mobilized donors and G-CSF + Plerixafor donors. You can request them here. 

Advantages of Mobilized CD34+ Stem Cells

  • Greater cell yields
  • Matches current transplantation procedures
  • Less invasive donation
  • May contain other cell types (e.g., endothelial progenitors or mesenchymal stromal cells)


Still using bone marrow stem cells in your research and development efforts?

Try mobilized CD34+ stem cells to see the difference.


  1. Thank you for sharing that stem cell is less invasive compared to bone marrow. The other day my doctor recommended stem cell treatment for my mother, who has arthritis. I will share this article with my mother so that she knows the procedure.

    • Please understand that we are only referring to research use of these cells. Stem cells for bone marrow transplant are a very specific case. Stem cells for other purposes are still experimental and unproven.

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