DNA molecules are some of the most important molecules in biology and their creation, both natural and artificial, is studied and widely used in many scientific fields.

In general, natural DNA synthesis occurs by first having the gene split and create a second identical DNA strand in a process called DNA replication. Enzymes unwind the DNA strand and split it apart, creating a replication fork. When the cell divides, it creates a duplicate genome, ensuring the new cell has a complete set of chromosomes.

Specific proteins are then used to aid in the replication and synthesis of the new genetic strands. These helper proteins are called primers. RNA primers are the only naturally occurring primers, however, artificial synthesis can use both RNA and DNA primers.

A major difference between natural and synthetic DNA synthesis is that in natural synthesis the enzymes can only synthesize in one direction whereas artificial synthesis does not have this directional limitation. Additionally, artificial gene synthesis is based on solid-phase DNA Synthesis.

Oligonucleotide synthesis is the artificial chemical process of creating short strands of nucleic acids with specific sequences. Synthetic DNA printing differs from molecular cloning and polymerase chain reaction (PCR) because it does not require a pre-existing gene sequence.

DNA oligo synthesis is done by adding one nucleotide to the end of the desired chain at a time. Each addition is referred to as a synthetic cycle, or the phosphoramidite method, and undergoes four steps:

1. De-blocking (detritylation)
2. Coupling
3. Capping
4. Oxidation

There are various techniques and applications involved in DNA synthesis that provide high-quality results, some of which will we cover below.