Ten years of cosmids

In this article we will review the ten years' work on cloning with cosmids and reminisce on a most successful collaboration. After 1978, cloning with cosmids became rapidly established worldwide, and has remained the most convenient system for cloning gene-sized fragments from complex genomes and whole operons from microorganisms. We will describe the development and principles of the method emphasizing the use of cosmids for manipulating and shuttling defined units (‘cassettes’) between microorganisms, and subsequently into plants, and in and out of animal cells. We will then discuss the future of the cosmid as an essential tool in the repertoire required for genome analysis and megasequencing.