Genetic engineering is the altering of an organism's deoxyribonucleic acid (DNA) to create a desired effect. Genetic engineers follow a set of techniques that allows them to remove genetic material from two or more species, recombine the genetic material (to create recombinant DNA), and integrate it into a host's genome, or genetic material. Genetic engineering is used for a variety of scientific, agricultural, and medical purposes.

Restriction Enzymes

All recombinant DNA technology requires the use of restriction enzymes. These enzymes are naturally occurring in bacteria that fight phage, or virus, DNA, but geneticists can use restriction enzymes as tools to cut DNA into manageable fragments.

Restriction enzymes recognize specific sequences along the DNA where it can be cut. These sequences contain four or more bases and occur randomly, and each enzyme cuts at a different sequence. Most restriction enzymes cut double-stranded DNA in a staggered fashion...