This project seeks to determine whether DNA evidence that has been deemed inadequate for PCR-based genotyping be restored to a usable condition if pre-treated with mixtures of DNA repair proteins. The efforts will focus on the application of cell extracts isolated from repair proficient organisms. In principle, extracts contain the full complement of DNA repair functions in the organism from which the extract was obtained. The work will take advantage of the range of DNA repair activities associated with Escherichia coli and Deinococcus radiodurans in development of reagents to assist in restoring damaged forensic evidence to a usable condition. Extracts will be modified by the engineering of strains to facilitate convenient removal of activities (such as nucleases) that could damage forensic samples and interfere with repair. Once suitable conditions are established, repair methodology focused on forensic markers will be explored.