Purification of DNA repair protein complexes from mammalian cells

Cells possess multiple DNA repair pathways to tackle a variety of DNA lesions. Often, DNA repair proteins function as large protein complexes. Here, we describe a protocol to purify DNA repair protein complexes from nuclei of mammalian cells. The method permits purification of protein complexes contain-ing stable as well as transiently associated proteins, which subsequently can be identified by mass-spectrometry analysis. This protocol can be applied to un-cover the functions and mechanism of DNA repair pathways.For complete information on the use and execution of this protocol, please refer to Socha et al. (2020).