Recombinant DNA technology

Until the advent of gene cloning in the early 1970s, it was almost impossible to study individual genes, particularly eucaryotic genes, at a molecular level, as the technology for producing the required amounts of pure genic DNA did not exist. To some extent bacterial geneticists had overcome this problem by linking certain bacterial genes to phage genomes (by using transducing phages), but no similar method was available to eucaryotic geneticists. Thus, until the advent of gene cloning, a technique which itself was only made possible by the discovery of restriction endonucleases, little was known about the molecular structure and the functioning of eucaryotic genes; recombinant DNA technology and gene cloning overcome this problem by linking eucaryotic (or procaryotic) genes to plasmid or phage vectors which can be easily replicated in a bacterial host.