Editing Recombinant DNA (section)

==Production==
[[File:Gene cloning.svg|thumb|300px]]
{{main|Molecular cloning}}

Molecular cloning is the laboratory process used to produce recombinant DNA.<ref name="isbn0-201-75054-6">{{cite book |author1=Campbell, Neil A.  |author2=Reece, Jane B..  |name-list-style=amp |title=Biology (6th ed.) |publisher=Addison Wesley |location=San Francisco |year=2002 |pages=375–401 |isbn=978-0-201-75054-6 }}</ref><ref name="isbn0-8153-4111-3">{{cite book |author1=Peter Walter |author2=Alberts, Bruce |author3=Johnson, Alexander S. |author4=Lewis, Julian |author5=Raff, Martin C. |author6=Roberts, Keith |title=Molecular Biology of the Cell (5th edition, Extended version) |publisher=Garland Science |location=New York |year=2008 |isbn=978-0-8153-4111-6 }}.{{pn|date=December 2024}} Fourth edition is available online through the NCBI Bookshelf: [https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=mboc4 link]</ref><ref name=isbn1-4292-2936-5>{{cite book |author1=Berg, Jeremy Mark |author2=Tymoczko, John L. |author3=Stryer, Lubert |title=Biochemistry, 7th ed. (Biochemistry (Berg)) |publisher=W.H. Freeman & Company |year=2010 |isbn=978-1-4292-2936-4 }}{{pn|date=December 2024}} Fifth edition available online through the NCBI Bookshelf: [https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=stryer link]</ref><ref name="isbn0-7167-2866-4">{{cite book |author=Watson, James D. |title=Recombinant DNA: Genes and Genomes: A Short Course |publisher=W.H. Freeman |location=San Francisco |year=2007 |isbn=978-0-7167-2866-5 }}</ref> It is one of two most widely used methods, along with [[polymerase chain reaction]] (PCR), used to direct the replication of any specific DNA sequence chosen by the experimentalist. There are two fundamental differences between the methods. One is that molecular cloning involves replication of the DNA within a living cell, while PCR replicates DNA in the test tube, free of living cells. The other difference is that cloning involves cutting and pasting DNA sequences, while PCR amplifies by copying an existing sequence.

Formation of recombinant DNA requires a [[Vector (molecular biology)|cloning vector]], a DNA molecule that replicates within a living cell. Vectors are generally derived from [[plasmid]]s or [[virus]]es, and represent relatively small segments of DNA that contain necessary genetic signals for replication, as well as additional elements for convenience in inserting foreign DNA, identifying cells that contain recombinant DNA, and, where appropriate, expressing the foreign DNA. The choice of vector for molecular cloning depends on the choice of host organism, the size of the DNA to be cloned, and whether and how the foreign DNA is to be expressed.<ref name="isbn0-87969-576-5">{{cite book |author1=Russell, David W. |author2=Sambrook, Joseph |title=Molecular cloning: a laboratory manual |publisher=Cold Spring Harbor Laboratory |location=Cold Spring Harbor, N.Y |year=2001 |isbn=978-0-87969-576-7 |url-access=registration |url=https://archive.org/details/molecularcloning0000samb_p7p5 }}</ref> The DNA segments can be combined by using a variety of methods, such as restriction enzyme/ligase cloning or [[Gibson assembly]].{{cn|date=October 2023}}

In standard cloning protocols, the cloning of any DNA fragment essentially involves seven steps: (1) Choice of host organism and cloning vector, (2) Preparation of vector DNA, (3) Preparation of DNA to be cloned, (4) Creation of recombinant DNA, (5) Introduction of recombinant DNA into the host organism, (6) Selection of organisms containing recombinant DNA, and (7) Screening for clones with desired DNA inserts and biological properties.<ref name="isbn0-7167-2866-4" />
''These steps are described in some detail in a related article ([[molecular cloning]]).''