Gene Cloning in Prokaryotes
Success in genetic engineering has been possible due to rapid development in gene cloning methodologies. It is essentially the insertion of a specific fragment of foreign DNA into a cell, through a suitable vector, in such a way that inserted DNA replicates independently and transferred to progenies as a result of cell division. The transformed cells containing DNA after their characterization and confirmation can be used commercially for the production of useful compounds such as insulin, interferon, growth hormones, etc. Maniatis
et al. (1976) have described the basic techniques of gene cloning. The principal steps of cDNA preparation shown in Fig. 2.13 are briefly described.