Critical assessment of microscopy methods for detecting single- and double-strand DNA breaks

A laboratory toolbox for detecting and quantifying DNA breaks in animal cells and tissues includes various methods that employ biochemical tests, DNA sequencing, or imaging approaches. Various methods based on microscopy were developed to detect DNA breaks in fixed and live cells, including the nick translation assay, TUNEL, STRIDE, and detection methods based on imaging of histone modifications (γH2A.X), recruitment of repair factors (XRCC1, PCNA, 53BP1, Rad51) or poly-ADP-ribosylation. This review discusses the advantages and limitations of various microscopy-based methods for the detection and quantification of single- and double-strand DNA breaks.