Located near the center of the US population, Northwest Arkansas is, quite simply, in the middle of everywhere. There are several Midwestern markets within a half-day's drive, including Kansas City, St. Louis, Dallas-Fort Worth, Little Rock, Tulsa, and Oklahoma City.
Restriction enzyme. A restriction enzyme or restriction endonuclease is an enzyme that cuts DNA at or near specific recognition nucleotide sequences known as restriction sites.
The discovery of enzymes that could cut and paste DNA made genetic engineering possible. These enzymes, restriction enzymes, are found naturally in bacteria, can be used to cut DNA fragments at specific sequences, while another enzyme, DNA ligase, can attach or rejoin DNA fragments with complementary ends.