Modulation of DNA strand break formation by repair modifiers in peripheral lymphocytes and hematopoietic cells after exposure to EtNU.

Cells were isolated from peripheral blood (A) or from CB (B,C) and exposed to EtNU (50 μg/mL; 20 minutes; white column) or were pretreated with different repair modifiers for 30 minutes prior to and throughout EtNU exposure (black columns). Modifiers were applied alone or in combinations: methoxyamine (Mx; 5 mM); aphidicolin (A; 1 mM); and fludarabine (F; 20 nM). To monitor the contribution of different DNA repair pathways, cells were analyzed directly after EtNU exposure by comet analysis (see Figure 3).