Fig. 1

Growth kinetics and clonogenic potential. A Exemplary phase contrast images of MSCs from MDS patient P06 cultured with media containing fetal bovine serum (FBS) or xeno-free (XF) medium for 12 days. Cells cultured with XF showed a higher confluence after 7 days. Scale: 200 µm B Total cell number obtained upon culturing healthy or MDS MSCs in FBS or XF media. Significantly higher cell numbers were received during expansion with XF compared to FBS for healthy MSCs after 3 days of culture and for MDS MSCs after 5 days of culture (Statistical significance is specified with asterisks ***p ≤ 0.001, ****p ≤ 0.0001). C Cell area was measured in representative images from day 5 of culture for n = 7 healthy samples and n = 7 MDS samples using ImageJ. The graph shows the mean cell area measured per microscopic view. (Statistical significance is specified with asterisks *p ≤ 0.05) D Average number of colonies generated per 100 cells at passage 2, by cells assayed in XF or FBS-containing medium (n = 4, P01, P02, P08 and P10). (Statistical significance is specified with asterisks *p ≤ 0.05). D Representative images of Giemsa staining without magnification showing more stained colonies with XF media compared to FBS