Abstract
Since the construction of the first generation of general cloning vectors in the early 1970s, a large number of cloning vectors have been developed. Despite the bewildering choice of commercial and other available vectors, the selection of cloning vector to be used can be decided by applying a small number of criteria: insert size, copy number, incompatibility, selectable marker cloning sites, and specialized vector functions. Several of these criteria are dependent on each other. Most general cloning plasmids can carry a DNA insert up to around 15 kb in size. Several types of vectors are available for cloning large fragments of DNA too. This chapter presents a consolidated account of some new generation of high-capacity vectors such as cosmid, yeast artificial chromosome (YAC) , bacterial artificial chromosome (BAC), P1 phage artificial chromosome (PAC), and human artificial chromosome (HAC).