The purpose of DNA Sequencing Protocols is to provide detailed practical procedures for the widest range of DNA sequencing meth ods, and we believe that all the vanguard techniques now being applied in this fast-evolving field are comprehensively covered. Sequencing technology has advanced at a phenomenal rate since the original methods were first described in the late 1970s and there is now a huge variety of strategies and methods that can be employed to determine the sequence of any DNA of interest. More recently, a large number of new and innovative sequencing techniques have been developed, including the use of such novel polymerases as Tag poly merase and Sequenase, the harnessing of PCR technology for linear amplification (cycle) sequencing, and the advent of automated DNA sequencers. DNA sequencing is surely one of the most important techniques in the molecular biology laboratory. Sequence analysis is providing an increasingly useful approach to the characterization of biological systems, and major multinational projects are already underway to map and sequence the entire genome of organisms, such as Escherichia coli, Saccharomyces cerevisiae, Caenorhabditis elegans, and Homo sapiens. Most scientists recognize the importance of DNA sequence data and perceive DNA sequencing as a valuable and indispensable aspect of their work. Recent technological advances, especially in the area of automated sequencing, have removed much of the drudg ery that was formerly associated with the technique, whereas innova tive computer software has greatly simplified the analysis and manipulation of sequence data.