Yield of clonogenic progenitors in liquid expansion culture.

At weeks 1 and 6 the number of granulocyte-macrophage and erythrocyte colony-forming units generated by B4-GFP– and GFP-transduced (MIG) progenitors cultured in serum-free medium supplemented with IL-3, IL-6, G-CSF, FL, and SF were quantified by plating aliquots of cells into methylcellulose and determining the number and morphology of colonies after 14 days (n = 3). *P < .01.