Analysis of CD34⁺CD59⁻ CD34⁺CD59⁺ cells from a normal volunteer. Cells were sorted based on the expression of CD34 and CD59 antigen (A) and placed in methylcellulose. After 2 weeks, the colonies were counted, and the cells were washed out of methylcellulose and stained with MoAbs directed against CD59 antigen (B). Bars represent erythrocyte (black) and myeloid (white) colony formation. (C) A histogram of progeny CD34⁺ derived from CD59⁺ (solid line) and CD34⁺ CD59⁻ (broken line) is shown. Log red fluorescence intensity versus cell number is plotted.