DNA replication profiling by molecular combing on single DNA fibers

In this protocol, the progression of DNA synthesis is profiled at a single-molecule resolution. DNA fibers are uniformly stretched on silanized coverslips, and replicating DNA can be traced with thymidine analogs using specific antibodies against distinct analogs. Single DNA fibers are visualized by an anti-single stranded DNA antibody. The protocol can be used to study DNA replication dynamics, the cellular response to replication stress, and replication fork progression at specific chromosomal regions when combined with fluorescent in situ hybridization. For complete details on the use and execution of this protocol, please refer to Conti et al. (2007), Fu et al. (2021), Kaykov et al. (2016), Redmond et al. (2018), and Schwob et al. (2009).