Nonradioactive detection of DNA repair synthesis

DNA repair is essential for the surveillance and maintenance of the integrity of the genome in response to various insults that damage DNA. The development of cell-free repair systems using radiolabeled nucleotide to monitor repair synthesis of exogenously introduced damaged-plasmid DNA has enabled the analysis of specific proteins required for repair synthesis. However, the hazards and the burgeoning cost of using radioisotopes have become significant factors in the laboratory. We describe here the use of digoxigenin-dUTP in place of radioactivity in a nonradioactive cell-free repair assay to detect DNA repair.