Oligonucleotides are short polymers and nuclei used in forensics, genetic testing, and research. They consist of 13-25 nucleotides and are made to hybridize to RNA or DNA sequences specifically.
Experts use solid-phase clinical synthesis to manufacture small bits of RNA or DNA for use in PCR (polymerase chain reaction), artificial gene synthesis, and library construction.
Oligonucleotide or oligo is used to detect specific sequences complementary to oligos. When certain sequences need to be detected, complementary oligos are synthesized in the lab.
Using these molecules as probes to detect is among the key functions of oligos. Examples of processes that use oligos in this form include FISH (fluorescent in situ hybridization), ASO analysis, Southern blot assay, and DNA microarrays.
How Oligonucleotides Are Made
Synthesis is the procedure used to make oligonucleotides. During synthesis, A, T, C, and G, the four nucleic acids, are often added in specified sequences to make nucleotide chains. Using phosphoramidite chemistry, Strings connect with the four nucleic acids to create a desired order.
What Oligonucleotides Are Used For
The most common application of oligos is polymerase chain reaction or PCR. Polymerase chain reaction is a technique used to make numerous copies of DNA strands or fragments, generating millions or thousands of more copies for other applications, such as sequencing or cloning.
Researchers often use oligonucleotides, which are between 20 and 35 bases long, referred to as primers, to start amplifying or copying. This primer is custom-designed to match target sequences of DNA. The capability of researchers to make their custom DNA oligonucleotides for experiments has opened many new doors in various fields, such as synthetic biology and molecular biology. These developments help in groundbreaking research, which makes the world safer, cleaner, and healthier.
Other Uses of Oligos
There are other applications of oligos in therapeutics and research. Three common applications of oligos include the following:
- Triplex-Forming Oligos: TFOs (Triplex-Forming Oligonucleotides) are oligos that fit in major DNA grooves. Generally, they are between 10 and 10 nucleotides long and often bind to DNA sequences, which have long sequences of pyrimidines on one strand and purine on another. TFOs can minimize gene expression by blocking transcription and are being researched for gene modification in targeted recombination to produce heritable modifications to DNA.
- Allele-Specific Testing: ASO (Allele-Specific Testing) probes are primarily used in dot-blots to detect genetic polymorphisms. In general, oligos are between 15 and 20 nucleotides long and are used to test for illnesses with common point mutations, like sickle-cell anemia and cystic fibrosis.
- Nucleic Acid Aptamers: Technically, aptamers are RNA or DNA sequences that bind with high affinity and specificity to a target. This specificity is because of the tertiary structures and not sequence per se.
Double-stranded (ss) and single-stranded (ds) oligos are helpful molecular tools in RNA and DNA research, therapeutics, and molecular diagnostics. Oligo-based primers for PCR have also transformed research in molecular biology. In addition, oligos, as well as their conjugates, are now applied in gene expression and as probes for in situ hybridization and microarrays.
