Review on cloning vector and expression vector

The advent of recombinant DNA technology has brought a series of dramatic changes in biology. It offered new opportunities for innovations to produce a wide range of therapeutic products. Recombinant DNA technology refers a series of procedures used to produce recombinant DNA (rDNA) molecules. The first step in recombinant DNA technology is to select a piece of DNA to be inserted into a vector. The second step is to cut that piece of DNA with a restriction enzyme and then ligate the DNA insert into the vector with DNA Ligase. And the third step is inserting the combination into host cells. A vector is a small piece of DNA molecule, which is used as a vehicle to artificially carry foreign genetic material into host cell, where it can be replicated and/or expressed. Vectors have three main features: origin of replication, multiple cloning sites and selectable marker. Cloning vector and expression vector are two types of vectors, used in recombinant DNA technology. A cloning vector is a small piece of DNA used to introduce genes into cells while obtaining numerous copies of the insert. Vectors used for cloning include: plasmids, bacteriophages, cosmids, bacterial artificial chromosomes (BACs), yeast artificial chromosomes (YACs) and human artificial chromosomes (HACs). Expression vectors are mainly plasmids, designed for the transcription and protein expression of the transgene. Since all vectors had been created to meet different purposes, each cloning vector and expression vector should clearly be described.