What are synthetic oligonucleotides?
Synthetic oligonucleotides (ODNs) are short nucleic acid chains that can act in a sequence specific manner to control gene expression. This new class of therapeutic agents can potentially target any abnormally expressed genes in a broad range of diseases from viral infections to psychoneurological disorders.
What are oligonucleotides used for?
Oligonucleotides are used as probes for detecting specific sequences that are complementary to the oligonucleotides. When a certain sequence needs to be detected, a complementary oligonucleotide is synthesized in the laboratory.
Who first chemically synthesized the oligonucleotide in vitro?
In the early 1950s, Alexander Todd’s group pioneered H-phosphonate and phosphate triester methods of oligonucleotide synthesis.
How are oligonucleotides synthesized in the laboratory?
Oligonucleotides are synthesized on solid supports. Typically, the support is a small column filled with control pore glass (CPG), polystyrene or a membrane. The oligonucleotide is usually synthesized from the 3′ to the 5′.
Who invented oligonucleotides?
Gobind Khorana became interested in the synthesis of oligonucleotides. He introduced two concepts to the field that made possible the convenient synthesis of oligonucleotides more than just a few bases long.
Where do oligonucleotides come from?
In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules.
How do oligonucleotides work?
Oligonucleotides readily bind, in a sequence-specific manner, to their respective complementary oligonucleotides, DNA, or RNA to form duplexes or, less often, hybrids of a higher order. This basic property serves as a foundation for the use of oligonucleotides as probes for detecting specific sequences of DNA or RNA.
How are oligonucleotides manufactured?
The oligonucleotide manufacturing process consists of five major steps, (1) synthesis, (2) cleavage and deprotection (C&D), (3) purification, (4) desalting and concentration and (5) lyophilization, as shown in Fig. 1. Additional steps can be added depending on the type of oligonucleotide being manufactured.
Where are nucleosides found?
Sources. Nucleosides can be produced from nucleotides de novo, particularly in the liver, but they are more abundantly supplied via ingestion and digestion of nucleic acids in the diet, whereby nucleotidases break down nucleotides (such as the thymidine monophosphate) into nucleosides (such as thymidine) and phosphate.
Which one is an oligonucleotide?
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics.
What is meant by oligonucleotide?
An oligonucleotide is a compound comprised of about three to twenty nucleotides. Each monomeric unit component is comprised of a nucleobase, a pentose moiety, and phosphate group. Oligonucleotides are short DNA or RNA molecules. They readily bind to complementary oligonucleotides or to nucleic acids, forming a duplex.
What are the protocols for the deprotection of oligonucleotides?
The protocols outline methods for deprotecting synthesizedoligonucleotides and for monitoring the progress of synthesis via the tritylassay. This unit augments the detailed instructions provided by the manufacturersof oligonucleotide synthesizers.
How are nucleosides incorporated in the middle of an oligonucleotide chain?
To be incorporated in the middle of an oligonucleotide chain using phosphoramidite strategy, the nucleoside analog must possess two hydroxy groups or, less often, a hydroxy group and another nucleophilic group (amino or mercapto).
How are exocyclic amino groups protected in oligonucleotide synthesis?
In routine oligonucleotide synthesis, exocyclic amino groups in nucleosides are kept permanently protected over the entire length of the oligonucleotide chain assembly. The protection of the exocyclic amino groups has to be orthogonal to that of the 5′-hydroxy group because the latter is removed at the end of each synthetic cycle.
Why are the protecting groups removed from a nucleoside?
To prevent undesired side reactions, all other functional groups present in nucleosides must be rendered unreactive (protected) by attaching protecting groups. Upon the completion of the oligonucleotide chain assembly, all the protecting groups are removed to yield the desired oligonucleotides.