Purpose: It is now feasible to detect DNA double strand breaks (DSB) in tissues by measuring the induction and resolution of DNA repair foci, such as gamma-H2AX, using immunofluorescent microscopy and digital image analysis. This review will highlight principal tools and approaches to tissue microscopy and analysis. It will also discuss the practical considerations of using microscopy in vitro and in vivo in measuring intranuclear foci following irradiation.
Conclusions: Computer-based image analysis algorithms allow an objective and quantitative analysis of foci and protein-protein interactions using 3D confocal images. Finally, we review the literature in which DNA repair foci have been investigated as a biodosimeter or a biomarker of DNA repair in normal tissues.