In general, the γH2AX assays share four important technical features: (i) a general acceptance for specificity to DSBs, (ii) sensitivity, (iii) quantification of DSBs, and (iv) repeatability and reproducibility. Regarding the technical supremacy of the specific methodology one can assign the following features: (i) specificity to DSBs: the γH2AX has been shown to detect specifically DSBs rather than other DNA damages . However, it has been reported that γH2AX can be formed at other types of lesions and in high frequencies in S-phase cells undergoing replication , or some other cell types undergoing for example chromatin remodeling , (ii) sensitivity: immunoassays utilizing specific antibodies for γH2AX show the highest score in sensitivity. Even one DSB can be detected by anti-γH2AX immunocytochemistry . The biology of γ-phosphorylation provides the explanation for this remarkable sensitivity; visualization of only one DSB in the whole nucleus is feasible, as γ-phosphorylation spans megabaselong domains in chromatin juxtaposed to the break, (iii) quantification: the presence of γH2AX detected by antibody based techniques can be quantified by various methods, such as confocal and epifluorescence microscopy (measured manually or automatically), flow cytometry, western blot quantification, etc.  and (iv) repeatability and reproducibility: to date, the repeatability and reproducibility of the method have been demonstrated by numerous diverse research laboratories all over the world, as demonstrated by the number of scientific publications .