Oligo

What are Oligonucleotides?

Oligonucleotides (oligo) are short nucleic polymer chains that bind to DNA and RNA sequences and are used in research, forensics and genetic testing. They are manufactured in a lab by a procedure called solid-phase chemical synthesis.

Uses:

Oligo are used in DNA microarrays, Southern blot assay, ASO analysis, artificial gene synthesis, DNA sequencing, polymerase chain reaction, and fluorescent in situ hybridization (FISH).

Purification of Oligonucleotides:

During the process Oligonucleotides are made, they may accumulate some impurities. This could be a problem in lab procedures which is why Oligo must be purified before they can be used in research. Few ways to purify them are gel filtration, HPLC, reverse HPLC, and anion-exchange HPLC and desalting.

Modification of Oligonucleotides:

Many research projects demand certain modified Oligos to carry out a lab procedure.

The following are some ways to modify Oligos.

• Biotinylation: Biotin is used for DNA and RNA detection. When a biotin is covalently attached to a nucleic acid, it is called Biotinylation.
• Fluorescent labeling (Dyomics™, Cy Dyes: More than 200 labels are available to choose from depending on your research details. Fluorescent labeling is the easier and most widely used method to modify oligos to use in detecting DNA sequences, forensics and such.
• Wobble bases: It is a mixture of bases that can be introduced to DNA at any position in oligo sequence. Such oligonucleotides are usually required for for random mutagenesis, and combinatorial chemistry.
• Phosphorylation: 5' or 3' phosphorylation can be done on oligonucleotides to help in research. 5' phosphorylation is needed when an oligo is used as a DNA ligase substrate. 3' phosphorylation inhibits 3' degeneration and by 3' exonucleases and to block DNA polymerase extension.
• Quenchers: Quenchers are used to absorb energy that is emitted by a fluorophore and while it is absorbing its energy, quenchers inhibits fluorophore's detection. Such modified oligos are important in various types of lab tests.