A model system for analysis of sibling BFU-Es, generated in unicellular erythroid culture (0.5 cell per well) supplemented with low dosages of IL-3 and GM-CSF and saturating levels of Epo.

The 4 sibling BFU-Es were subdivided and individually reseeded in unicellular erythroid culture: 3 siblings were treated with graded amounts of IL-3, GM-CSF, or KL ± HD inhibitor (NaB or TSA); the fourth control sibling was untreated. The sibling clones were analyzed on day 14 through day 18 as single or pooled mature erythroblast colonies.