Homology-directed repair

Patent Pending Homology directed repair (HDR) is a mechanism in cells to repair double strand DNA lesions. This repair mechanism can only be used by the cell when there is a homologue piece of DNA present in the nucleus, mostly in G2 and S phase of the cell cycle. When the homologue DNA piece is absent, another process called non-homologous end joining (NHEJ) can take place instead.