oligonucleotide

Examples of oligonucleotide in the following topics:

• Synthesizing DNA

  • Here we will focus on chemical synthesis of DNA, which is also known as oligonucleotide synthesis.
  • To obtain the desired oligonucleotide, the building blocks are sequentially coupled to the growing oligonucleotide chain in the order required by the sequence of the product.
  • The occurrence of side reactions sets practical limits for the length of synthetic oligonucleotides (up to about 200 nucleotide residues) because the number of errors accumulates with the length of the oligonucleotide being synthesized.
  • Products are often isolated by HPLC to obtain the desired oligonucleotides in high purity.
  • Oligonucleotides find a variety of applications in molecular biology and medicine.

• DNA Analysis Using Genetic Probes and PCR

  • Example of genetic analysis method using PCR and immobilized oligonucleotide probes: The reverse dot-blot method has several unique properties that are valuable in a diagnostic setting: (1) The typing that results from a single sample can be located on a single strip.
  • This minimizes user labor as well as error potential and allows the use of standardized reagents. (3) Unlike dot-blot/oligonucleotide typing, only the PCR product is labeled, eliminating the potential problem of probes labeled to different specific activities.
  • The use of molecular technology in the diagnoses of infectious diseases has been further enhanced by the introduction of gene amplication techniques, such as the polymerase chain reaction (PCR) in which DNA polymerase is able to copy a strand of DNA by elongating complementary strands of DNA that have been initiated from a pair of closely spaced oligonucleotide primers.

• Antisense Agents

  • Antisense agents are short oligonucleotides that bind to target messenger RNA and inhibit protein synthesis.

• Multiplex and Real-Time PCR

  • The PCR process can be divided into three steps: DNA denaturation where double-stranded DNA (dsDNA) is separated at temperatures above 90°C, oligonucleotide primers annealing at 50–60°C, and primer extension at 70–78°C.
  • Two common methods that are used to product detection in real-time PCR include the use of non-specific flourescent dyes that intercalate with double-stranded DNA or sequence-specific DNA probes that consist of oligonucleotides labeled with a fluorescent reporter (oligoprobes).

• Mutation

  • Site-directed mutagenesis, also called site-specific mutagenesis or oligonucleotide-directed mutagenesis, is a molecular biology technique often used in biomolecular engineering in which a mutation is created at a defined site in a DNA molecule.