When setting out to decide on the content of DNA Repair Protocols: Prokaryotic Systems, I was conscious of the need to portray the vast array of pathways and enzymatic activities that are part of the discipline of DNA repair. In addition to the classical DNA repair activities, I wanted to convey the significant interest that has been generated in recent years in the use of the proteins and repair systems as research tools, much like the use of restriction enzymes over the last few decades. Therefore, in addition to chapters deta- ing protocols for investigating specific repair activities, I...