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ion sequencing
Wednesday 28 March 2007
deep ion sequencing; Ion semiconductor sequencing
| WKP |
Definition: Ion Semiconductor Sequencing is a method of DNA sequencing based on the detection of hydrogen ions that are released during the polymerization of DNA.
This is a method of "sequencing by synthesis", during which a complementary strand is built based on the sequence of a template strand.
A microwell containing a template DNA strand to be sequenced is flooded with a single species of deoxyribonucleotide triphosphate (dNTP). If the introduced dNTP is complementary to the leading template nucleotide, it is incorporated into the growing complementary strand.
This causes the release of a hydrogen ion that triggers an ISFET ion sensor, which indicates that a reaction has occurred. If homopolymer repeats are present in the template sequence, multiple dNTP molecules will be incorporated in a single cycle. This leads to a corresponding number of released hydrogens and a proportionally higher electronic signal.
This technology differs from other sequencing technologies in that no modified nucleotides or optics are used.
Ion semiconductor sequencing may also be referred to as ion torrent sequencing, pH-mediated sequencing, silicon sequencing, or semiconductor sequencing.
The technology was licensed from DNA Electronics Ltd, developed by Ion Torrent Systems Inc. and was released in February 2010.
Ion Torrent have marketed their machine as a rapid, compact and economical sequencer that can be utilized in a large number of laboratories as a bench top machine.
Roche’s 454 Life Sciences is partnering with DNA Electronics on the development of a long-read, high-density semiconductor sequencing platform using this technology.
References
Deep ion sequencing of amplicon adapter ligated libraries: a novel tool in molecular diagnostics of formalin fixed and paraffin embedded tissues. Becker K, Vollbrecht C, Koitzsch U, Koenig K, Fassunke J, Huss S, Nuernberg P, Heukamp LC, Buettner R, Odenthal M, Altmueller J, Merkelbach-Bruse S. J Clin Pathol. 2013 Apr 25. PMID: 23618693
