SCF-mediated modulation of HbF in cord blood–derived erythroblasts.

The cells were grown for 14 days in EPO with or without SCF added on days 7 to 14 using identical culture conditions as those for the adult cells. (A) Hemoglobin distribution from flow cytometric analyses of HbF and HbA after staining with fluorescent antibodies (y-axis) versus cell size (x-axis) is shown for each culture condition. A negative fluorescence level (below horizontal bar) was determined using isotypic control antibodies. The percentage of positive cells is shown on the upper right corner of each panel. (B) Representative HPLC profiles from cells cultured in EPO alone (left) versus EPO plus SCF are shown for comparison. The HbF/HbA ratios from 3 separate donors are shown next to each HPLC profile (mean ratios ± SDs;P = .004).