Editing DNA sequencing (section)

==== Heliscope single molecule sequencing ====
Heliscope sequencing is a method of [[Single-molecule magnetic sequencing|single-molecule sequencing]] developed by [[Helicos Biosciences]]. It uses DNA fragments with added poly-A tail adapters which are attached to the flow cell surface. The next steps involve extension-based sequencing with cyclic washes of the flow cell with fluorescently labeled nucleotides (one nucleotide type at a time, as with the Sanger method). The reads are performed by the Heliscope sequencer.<ref>{{cite web|url=http://www.helicosbio.com/Products/HelicosregGeneticAnalysisSystem/HeliScopetradeSequencer/tabid/87/Default.aspx|archive-url=https://web.archive.org/web/20091102041828/http://www.helicosbio.com/Products/HelicosregGeneticAnalysisSystem/HeliScopetradeSequencer/tabid/87/Default.aspx|archive-date=2009-11-02|title=HeliScope Gene Sequencing / Genetic Analyzer System : Helicos BioSciences|date=2 November 2009}}</ref><ref>{{cite journal | vauthors = Thompson JF, Steinmann KE | title = Single molecule sequencing with a HeliScope genetic analysis system | journal = Current Protocols in Molecular Biology | volume = Chapter 7 | pages = Unit7.10 | date = October 2010 | pmid = 20890904 | pmc = 2954431 | doi = 10.1002/0471142727.mb0710s92 }}</ref> The reads are short, averaging 35 bp.<ref>{{cite web |url=http://seqll.com/technical-description/ |archive-url=https://web.archive.org/web/20140808055229/http://seqll.com/technical-description/ |url-status=dead |archive-date=8 August 2014 |publisher=SeqLL |access-date=9 August 2015 |title=tSMS SeqLL Technical Explanation}}</ref> What made this technology especially novel was that it was the first of its class to sequence non-amplified DNA, thus preventing any read errors associated with amplification steps.<ref>{{cite journal |last1=Heather |first1=James M. |last2=Chain |first2=Benjamin |title=The sequence of sequencers: The history of sequencing DNA |journal=Genomics |date=January 2016 |volume=107 |issue=1 |pages=1–8 |doi=10.1016/j.ygeno.2015.11.003 |pmc=4727787 |pmid=26554401 }}</ref> In 2009 a human genome was sequenced using the Heliscope, however in 2012 the company went bankrupt.<ref>{{cite book|author1=Sara El-Metwally |title=Next Generation Sequencing Technologies and Challenges in Sequence Assembly |volume=7 |author2=Osama M. Ouda |author3=Mohamed Helmy |publisher=Next Generation Sequencing Technologies and Challenges in Sequence Assembly, Springer Briefs in Systems Biology Volume 7 |year=2014 |pages=51–59|doi=10.1007/978-1-4939-0715-1_6 |chapter=New Horizons in Next-Generation Sequencing |series=SpringerBriefs in Systems Biology |isbn=978-1-4939-0714-4 }}</ref>