HbF reactivation in sibling BFU-E colonies.

(A) HbF reactivation in sibling BFU-Es grown in the presence of graded concentrations of GM-CSF or IL-3. HbF synthesis was evaluated in terms of γ-chain content in pooled sibling erythroid colonies. A representative experiment is shown. (B) Globin chain HPLC scans and percentage of F cells from pooled sibling BFU-E colonies grown in unilineage erythroid culture in the presence or absence of GM-CSF (1 ng/mL) (representative results).