Applications of Next-Generation Sequencing Technologies to Diagnostic Virology

Barzon, Luisa; Lavezzo, Enrico; Militello, Valentina; Toppo, Stefano; Palù, Giorgio

The first next-generation high-throughput sequencing technology, the 454 FLX pyrosequencing platform (http://www.454.com/), which was developed by 454 Life Sciences and later bought by Roche, became available in 2005. In early 2007, Illumina released the Genome Analyzer (http://www.illumina.com), developed by Solexa GA, and more recently, SOLiD was released by Applied Biosystems (http://www.appliedbiosystems.com). This field is in rapid expansion and novel and improved platforms are continuously being developed and released, like Heliscope by Helicos (http://www.helicosbio.com/), Ion Torrent PGM by Life Technologies (http://www.iontorrent.com/) and a real-time sequencing platform by Pacific Biosciences (http://www.pacificbiosciences.com/). While the platform developed by Pacific Biosciences, as well as other novel sequencing platforms, are referred as "third-generation" because they sequence processively single large DNA molecules without the need to halt between read steps, 454 pyrosequencing, Illumina GA and SOLiD methods represent the "second generation" systems, able to sequence populations of amplified template-DNA molecules with a typical "wash-and-scan" technique [1] . Given these criteria, Ion Torrent PGM and Heliscope sit between "second-" and "third-generation" technologies, since they do not completely fulfill the features assigned to each category.