This report describes a common method of obtaining template DNA from phagemids, phages and plasmids. The strategy is based on the use of the cationic detergent cetyl-trimethylammonium bromide (CTAB) for DNA precipitation. By avoiding phase separation, many manipulation steps are reduced. A time-saving modification to perform double-stranded DNA sequencing directly after alkaline-denaturation is also introduced. The protocols described here allow the researcher to obtain template DNA from a variety of initial sources, thus giving reproducible sequencing results when using T7 DNA polymerase.