[en] CD34-positive cells were isolated from a total of 23 cords using CellPro Ceprate columns. AIS MicroCellector flasks, and panning. The cells were (1) expanded in serum-free culture supplemented with a variety of combinations of cytokines and (2) immunophenotyped using multiple fluorochrome labeling. The results indicated that the avidin column produced the highest purity of CD34-positive cells, and that immature blast cells could be expanded in serum-free culture. Preliminary results suggested that the four fluorochrome labeling technique may provide useful information on the lineage commitment of cord blood precursor and blast cells.