Studies of Adult Peripheral Blood

A B S T R A C T By using a methylcellulose clonal assay, we cultured peripheral blood erythropoietic precursors from a patient with sickle cell anemia, a patient with sickle cell hemoglobin C disease, and a normal volunteer. We then analyzed the synthetic rates ofadult and fetal hemoglobins (Hb) in individual erythropoietic bursts. Hb were labeled with '4C-amino acids in culture, separated by slab gel isoelectric focusing techniques, and quantitated by fluorographic methods. All bursts exhibited both fetal and adult Hb in varying ratios. Frequency distributions of the individual bursts differing in percentage ofHbF biosynthesis approached normal distributions. Further stimulation ofHbF synthesis by higher erythropoietin in culture was associated with increased HbF biosynthesis in individual bursts. Augmentation of human HbF synthesis in culture appears to be controlled by (qualitative intracellular changes rather than by changes in cellular population.