Repair kinetics for secondary DNA lesions in hematopoietic cells.

CD34⁺ or CD34⁻ cells were isolated from samples of CB (A,B) or BM (C,D) of 4 individual donors and exposed ex vivo to a short treatment (20 min) with EtNU (100 μg/mL). Repair-induced DNA strand breaks were determined by the comet assay in cell aliquots at different time points after exposure.