Editing DNA synthesis (section)

==Gene synthesis==
[[Artificial gene synthesis]] is the process of synthesizing a [[gene]] ''[[in vitro]]'' without the need for initial template DNA samples.
In 2010 [[J. Craig Venter]] and his team were the first to use entirely synthesized DNA to create a self-replicating microbe, dubbed [[Mycoplasma laboratorium]].<ref name = "Fikes" />

===Oligonucleotide synthesis===
[[Oligonucleotide synthesis]] is the chemical synthesis of sequences of nucleic acids. The majority of biological research and bioengineering involves synthetic DNA, which can include [[oligonucleotide]]s, synthetic genes, or even [[chromosome]]s. Today, most synthetic DNA is custom-built using the [[Nucleoside phosphoramidite|phosphoramidite]] method by [[Marvin H. Caruthers]]. Oligos are synthesized from building blocks which replicate natural bases. Other techniques for synthesising DNA have been commercially made available, including Short Oligo Ligation Assembly.<ref>https://telesisbio.com/gibson-sola-platform/</ref> The process has been automated since the late 1970s and can be used to form desired genetic sequences as well as for other uses in medicine and molecular biology. However, creating sequences chemically is impractical beyond 200-300 bases, and is an environmentally hazardous process. These oligos, of around 200 bases, can be connected using DNA assembly methods, creating larger DNA molecules.<ref>{{cite journal |last1=Palluk |first1=Sebastian |last2=Arlow |first2=Daniel H |display-authors=et al <!--Sebastian Palluk, Daniel H Arlow, Tristan de Rond, Sebastian Barthel, Justine S Kang, Rathin Bector, Hratch M Baghdassarian, Alisa N Truong, Peter W Kim, Anup K Singh, Nathan J Hillson & Jay D Keasling -->|title=De novo DNA synthesis using polymerase-nucleotide conjugates |journal=Nature Biotechnology |date=2018 |volume=36 |issue=7 |pages=645–650 |doi=10.1038/nbt.4173|pmid=29912208 |osti=1461176 |s2cid=49271982 }}</ref>

Some studies have explored the possibility of enzymatic synthesis using [[terminal deoxynucleotidyl transferase]] (TdT), a DNA polymerase that requires no template. However, this method is not yet as effective as chemical synthesis, and is not commercially available.<ref>{{cite journal |last1=Perkel |first1=Jeffrey M. |title=The race for enzymatic DNA synthesis heats up |journal=Nature |date=2019 |volume=566 |issue=7745 |page=565 |doi=10.1038/d41586-019-00682-0 |pmid=30804572 |bibcode=2019Natur.566..565P |doi-access=free }}</ref>

With advances in artificial DNA synthesis, the possibility of [[DNA data storage]] is being explored. With its ultrahigh storage density and long-term stability, synthetic DNA is an interesting option to store large amounts of data. Although information can be retrieved very quickly from DNA through next generation sequencing technologies, de novo synthesis of DNA is a major bottleneck in the process. Only one nucleotide can be added per cycle, with each cycle taking seconds, so the overall synthesis is very time-consuming, as well as very error prone. However, if biotechnology improves, synthetic DNA could one day be used in data storage.<ref>{{cite journal |last1=Tabatabaei |first1=S. Kasra |title=DNA punch cards for storing data on native DNA sequences via enzymatic nicking |journal=Nature Communications |date=2020 |volume=11 |issue=1 |page=1742 |doi=10.1038/s41467-020-15588-z|pmid=32269230 |pmc=7142088 |bibcode=2020NatCo..11.1742T |doi-access=free }}</ref>

===Base pair synthesis===
It has been reported that new [[nucleobase]] pairs can be synthesized, as well as A-T ([[adenine]] - [[thymine]]) and G-C ([[guanine]] - [[cytosine]]). Synthetic nucleotides can be used to expand the genetic alphabet and allow specific modification of DNA sites. Even just a third base pair would expand the number of amino acids that can be encoded by DNA from the existing 20 amino acids to a possible 172.<ref name="Fikes">{{cite news|url=http://www.utsandiego.com/news/2014/may/08/tp-life-engineered-with-expanded-genetic-code/ |title=Life engineered with expanded genetic code |last=Fikes |first=Bradley J. |date=May 8, 2014 |work=San Diego Union Tribune |access-date=8 May 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140509001048/http://www.utsandiego.com/news/2014/may/08/tp-life-engineered-with-expanded-genetic-code/ |archive-date=9 May 2014 }}</ref> 
[[Hachimoji DNA]] is built from eight nucleotide letters, forming four possible base pairs. It therefore doubles the information density of natural DNA. In studies, RNA has even been produced from hachimoji DNA. This technology could also be used to allow data storage in DNA.<ref>{{cite journal |last1=Hoshika |first1=Shuichi |title=Hachimoji DNA and RNA. A Genetic System with Eight Building Blocks |journal=Science |date=2020 |volume=363 |issue=6429 |pages=884–887 |doi=10.1126/science.aat0971 |pmid=30792304|pmc=6413494 }}</ref>