DNA synthesis is the natural or artificial creation of deoxyribonucleic acid (DNA) molecules. The term DNA synthesis can refer to DNA replication - DNA biosynthesis (in vivo DNA amplification), polymerase chain reaction - enzymatic DNA synthesis (in vitro DNA amplification) or gene synthesis - physically creating artificial gene sequences.
In nature, DNA molecules are created by all living cells through the process of DNA replication, with replication initiator proteins splitting the cell's DNA and copying each split strand, with the copied strands then joining together with their template strand into a new DNA molecule. Various means exist to artificially stimulate the replication of naturally occurring DNA, or to create artificial gene sequences. The process of DNA replication occurs typically as part of cell division, during interphase.
Polymerase chain reaction
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.
Oligonucleotide synthesis is the chemical synthesis of sequences of nucleic acids. 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.
Base pair synthesis
New nucleobase pairs can also be synthesized, A-T (adenine - thymine) and G-C (guanine - cytosine). 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.