New benchtop sequencers ship; sequence genome in under a day
Life Technologies began shipments of its new benchtop sequencing instrument on Thursday, but the sequencing race is still on. Illumina, based in San Diego, California, and Oxford Nanopore of Oxford, UK, have also promised new machines by the end of the year, each capable of sequencing a human genome in less than a day.
Greg Lucier, chief executive of Life Technologies, which is based in Carlsbad, California, says that well over 100 new machines, the Ion Proton, have been ordered. The machine costs US$150,000 and performs 4-hour sequencing runs using $1,000 disposable chips. A chip can sequence 60-80 million filtered DNA fragments of lengths of up to 200 bases, enough to provide several-fold coverage on a human exome (the protein-encoding genes). A second-generation chip capable of sequencing a full human genome is scheduled for release next year.
Each company’s machine reads DNA bases in different ways. Illumina’s machine reads different colours of light depending on whether A, C, T or G is incorporated. The Ion Proton detects tiny changes in pH as different bases are added, and Oxford Nanopore’s machine detects disruption in an electrical current as a single DNA molecule slides through a nano-sized hole. Nanopore promises to be quickest and cheapest, but it has higher error rates than Illumina or Ion Torrent machines. Also, Nanopore has not yet publicly released its instruments or data, so researchers are still unsure how the technology will perform.