Oligonucleotide Synthesis and Purification

Oligonucleotide synthesis is the chemical synthesis of nucleic acids to assemble a defined sequence. In contrast to enzymatic synthesis, which in nature proceeds in a 5′ to 3′ direction, synthetic oligonucleotide synthesis predominantly takes place in the 3′ to 5′ orientation. The process of oligonucleotide synthesis has evolved since the early 1950s, although the basic solid-phase synthesis methods that are currently used for the assembly of oligonucleotides have been in place for nearly 30 years. These methods rely primarily on nucleoside phosphoramidite (amidite) chemistry.1–3 Recently, the field of oligonucleotide chemistry has broadened with the introduction of new monomers, activation chemistries, and solid supports. This has enabled the creation 3