Genome-wide analysis of DSBs sites in HEK293T cells

For genome-wide identification and analysis of endogenous DSBs in HEK293T cells chromosomes the ligation-mediated PCR and deep sequencing of the DSBs library were used. The cells were included in low-melt agarose, and the plugs were used for isolation of DNA in a solid phase using incubation in the solution containing 0.5 M EDTA (pH 9.5), 1% sodium laurylsarcosine, and 1-2 mg of proteinase K per ml for 40-48 hr at 50°C. Then DNA was isolated by electro-elution and used for ligation with biotinylated ds-adapter. To shorten large DNA molecules the digestion with Sau3A endonuclease was performed. Then the short regions of DNA attached to DSBs sites were selected using the streptavidin magnespere paramagnetic particles. To prepare samples for amplification of DSBs library the Sau3A adapter was ligated at the opposite to DSBs sites. PCR amplification was performed using the primers corresponding to biotinylated and Sau3A adapters. The library was used for paired end sequencing. The corresponding reads were processed and used for analysis of their distribution in human genome. Overall design: Analysis of human epigenome by the genome-wide analysis of DSBs