Fig. 4.
Variation of HbF synthesis among sibling BFU-E clones in 9 experimental groups.
At variance with the standard protocol (Figure 1), the 4 sibling colonies within each group were identically treated, ie, the 4 sibling wells were supplemented with 0, 1, or 100 ng KL. Correlation between percentage values of F cells and cell number × 103per colony: r = 0.8603, P < .0001.