Molecular cloning is a set of experimental steps in which recombinant DNA is assembled from a species to be cloned, and a species that will serve as the host for replication. The ability to use RNA-directed DNA synthesis allows researchers to obtain a clone library representative of the RNA population (or specific members thereof) in the cells of interest.
In general, molecular cloning experiments use a laboratory strain of the bacterium E. coli and a plasmid cloning vector as the host DNA. Cloning vectors typically have at least one restriction endonuclease recognition site that, upon treatment with the appropriate enzyme, will be prepared to accept foreign DNA treated with the same endonuclease(s). The vector and foreign DNA are then ligated together, typically using a phage-encoded DNA ligase, and then transformed into host cells. The cloning vector usually contains a selectable genetic marker, generally a gene that confers antibiotic resistance, so that when the cells are grown in medium containing the antibiotic, only cells that have been successfully transformed with vector DNA will grow. Cloning vectors typically have an additional gene that allows the experimenter to differentiate between vectors that have integrated the foreign DNA and those that have not. The clones that have foreign DNA inserts can then be selected for use in downstream studies
- Cooper, Geoffery M. The Cell: A Molecular Approach. 4th ed. Washington D.C.: ASM
Press, 2007. 118-128.
- McKee, Trudy. Biochemistry: The Molecular Basis of Life. 4th ed. New York: Oxford
University Press, 2009. 701-2.