Pyrosequencing is a method of DNA sequencing that detects light emitted during the sequential addition of nucleotides during the synthesis of a complementary strand of DNA. Image Credit: ustas7777777 / Shutterstock Pyrosequencing can be used to detect DNA and RNA from almost any source, and has applications in bacteria resistance screening, drug development, epigenetics, and many other fields. Process of PyrosequencingPyrosequencing occurs in six major steps:
If no light is emitted upon the addition of cytosine, then the next complimentary base in the single-strand DNA template must be one of the other three nucleotides. It should be noted that of the four nucleotides added during pyrosequencing, deoxyadenosine triphosphate (A) is replaced with deoxyadenosine α-thio triphosphate to avoid a false signal from early reaction with luciferase. The method is limited to around 300-500 nucleotide base pairs, compared with the greater chain lengths of over 1000 base pairs achievable using Sanger sequencing. It is, however, less expensive and commercially available. Applications of pyrosequencingPyrosequencing Pyrosequencing is used to reveal the genetic code of a section of DNA. It is also able to detect single nucleotide polymorphisms, insertion-deletions or other sequence variations, in addition to being able to quantify DNA methylation and allele frequency. For example, genome regions associated with a genetic disorder can be narrowed down further to identify specific genes and variations within them, or an inherited negative response to certain drugs can be checked for before the drug is prescribed. The method of drug resistance in a new strain of bacteria can be determined by its genetic change compared to an ancestor, or epigenetic methylation of DNA in a cancer cell can be detected in order to determine the best course of treatment. Further Reading
Last Updated: Oct 31, 2018
Written by Michael GreenwoodMichael graduated from Manchester Metropolitan University with a B.Sc. in Chemistry in 2014, where he majored in organic, inorganic, physical and analytical chemistry. He is currently completing a Ph.D. on the design and production of gold nanoparticles able to act as multimodal anticancer agents, being both drug delivery platforms and radiation dose enhancers. CitationsPlease use one of the following formats to cite this article in your essay, paper or report:
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