The new Ion Torrent sequencer will also allow researchers to buy a chip that sequences only exons, the regions of the genome that encode proteins. Exons only account for about 5 percent of the human genome, according to the National Human Genome Research Institute, but they are where most disease-causing mutations occur, making so-called exome sequencing a faster and potentially cheaper option for many researchers. Although it’s the same price as the genome chip, the Ion Torrent exome chip can sequence two exomes at a time, bringing the per-sequence cost down to $500.
“Some researchers want to sequence single genes, others want to do exomes, and others—for example, cancer researchers—will want to sequence whole genomes, so all three are going to coexist,” says Rothberg. “It’s about finding the right tool for the problem.”
Whether Ion Torrent’s new technology will be enough to make it the dominant supplier of these tools remains to be seen. A day after the company debuted the Proton sequencer, Illumina also announced that it, too, had reached the $1,000 genome milestone.
“It’s a volatile field, and there’s no sentiment to keep researchers from switching to new technologies,” says Gibbs. Still, Ion Torrent clearly has the price advantage. For researchers who already have Illumina’s latest sequencer, the price to upgrade will be only $50,000, but the retail price will be $740,000, which will likely scare off most newcomers.