A-C. Hematopoietic potential of human BM MNCs derived from young and old donors. We found a statistically significant higher hematopoietic potential of young BM MNCs both in the investigation of colony forming units for granulocytes and macrophages (A; CFU-GM) and of erythroid burst forming units (B; BFU-E). This observation was supported by a 2-fold decrease of CD34+ hematopoietic stem cells in old BM MNCs (C). The vitality of CD34+ cells in both groups was above 90% and did not differ age-dependently (D). Values are means ± SD for 4 samples, each comprising three technical replicates, per group. *p < 0.05, §p = 0.063 by t-test.