A comprehensive collection of readily reproducible techniques for the manipulation of recombinant plasmids using the bacterial host E. coli. The authors describe proven methods for cloning DNA into plasmid vectors, transforming plasmids into E. coli, and analyzing recombinant clones. They also include protocols for the construction and screening of libraries, as well as specific techniques for specialized cloning vehicles, such as cosmids, bacterial artificial chromosomes, l vectors, and phagemids. Common downstream applications such as mutagenesis of plasmids, recombinant protein expression, and the use of reporter genes, are also described.