ABSTRACT
Genetic Engineering refers to the alteration of cellular DNA by means and methods other than normal sexual or mutational phenomena. Thus, this technology involves techniques in which DNA may be cut, rejoined, its sequence determined, or a segment altered in sequence to suit an intended use. For example, a DNA fragment may be isolated from one organism, spliced into other DNA fragment [the vector], and put into a bacterium or other organism. Many identical copies can thus, be made of the original DNA fragment. There are atleast two basic objectives of genetic engineering technology viz. to learn about the ways, the nature works and to make use of this knowledge for practical purposes. The two basic tools that are used in genetic engineering technology i. e. the "Vectors" or "Vehicles" [e. g. plasmids, cosmids, shuttle vectors and transposons] and "Restriction Enzymes" [e. g. restriction endonucleases] are being discussed at length