The Homologous Recombination (HR) DNA Repair Antibody Sampler Kit provides an economical means of detecting proteins involved in HR DNA repair. The kit includes enough antibodies to perform two western blot experiments with each primary antibody.

DNA double-strand breaks (DSBs) are potentially hazardous lesions that can be induced by ionizing radiation (IR), radiomimetic chemicals, or DNA replication inhibitors. Cells recognize and repair DSBs via two distinct but partly overlapping signaling pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). DSBs that arise during S or G2 phase are repaired via HR, using the replicated sister chromatid as a repair template (1). Activation of ATM by autophosphorylation on Ser1981 occurs in response to exposed DNA DSBs. ATM regulates various responses to DNA damage, including regulation of HR factors (2). Rad51 recombinase polymerizes and forms a filament along single-stranded DNA, mediating HR with the help of auxiliary proteins, including Rad54 and BRCA2 (3). BRCA2 has been shown to be required for localization of Rad51 to sites of DSBs, and cells lacking BRCA1 and BRCA2 cannot repair DSBs through HR (4). NBS1 is critical for HR, and requires CDK-dependent association with CtIP and subsequent phosphorylation by ATM at Ser278 and Ser343 (5-6).