Time course of mast cell development from CD34+ cord blood cells in serum-deprived liquid cultures. (A) CD34+ cord blood cells (1 × 105) were cultured in each well containing 10 mL of serum-deprived liquid culture medium supplemented with 10 ng/mL of SCF. The number of viable cells was serially counted, and the results presented are corrected for demipopulation. Similar results were obtained in the other two experiments. Values are expressed as the mean ± SD. (B) The single CD34+ cord blood cells were sorted into the individual wells of a 96-well culture plate containing 10 ng/mL of SCF, as described in Materials and Methods. The number of cells in each well was serially counted until 4 weeks. The cell growth of a total of 15 colonies that generated more than 50 cells positive for tryptase at 4 week is shown.
