Representative FACS analysis of purity of CFU-GM–, BFU-E–, and CFU-MEG–derived cells.

The expression of CD33 (A), GPA-A (B), and CD41 (C) on (A) human CFU-GM–, (B) BFU-E–, and (C) CFU-Meg–derived cells (myeloblasts, erythroblasts, and megakaryoblasts, respectively). Lineage-specific cells were expanded from CD34⁺ cells under serum-free conditions as described in “Materials and methods.”