Non-frozen preservation of committed hematopoietic stem cells from normal human bone marrow.

We examined the optimal conditions for maintaining normal human hematopoietic stem cells without cryopreservation. The effects of serum, HEPES, CPD and storage temperature were studied. Stem cell integrity (CFU-c, CFU-e, and BFU-e) was optimally maintained when the bone marrow cells were suspended in a medium containing 40% fetal calf serum, 25 mM HEPES, and 12.28% CPD and maintained at 4 degrees C. For example, under these storage conditions the recovery of functionally intact early erythroid stem cells, BFU-e, was 84% after 2 days, 44% after 4 days and 12% after 7 days. These results indicate that non-frozen short-term storage of human bone marrow may be of clinical utility in bone marrow transplantation.