manufacturer’s instructions. Briefly, lineage-depleted BM cells were stained with
HSC-defining antibodies before washed and incubated with camptothecin at a final
concentration of 5 μM for 5 hours at 37°C. The samples were then washed with
ice-cold FACS buffer and resuspended in 1X Annexin binding buffer, to which Annexin V and
PI were added. The samples were vortexed and incubated in the dark for 15 minutes at room
temperature. Additional Annexin binding buffer was then added after which the samples were
analyzed within one hour.