At this point, Ion Torrent’s technology isn’t well-suited to sequencing entire human genomes. Moore’s sequence required about 1,000 chips and a total cost of about $200,000. Other technologies, in contrast, have brought the cost of a whole genome down to $5,000 to $20,000, depending on how the cost is calculated.
Ion Torrent’s technology is most adept at sequencing small genomes, like those of microbes, or a selection of genes, such as those that have been linked to cancer. “We are not the cheapest machine for a human genome, but we are the cheapest if you want to look at 200 genes or a pathogen behind an outbreak,” says Rothberg. He predicts that by 2013, Ion Torrent will have developed a chip capable of sequencing an entire human genome.
However, many of the most medically relevant tests that physicians want to run today encompass only tens or hundreds of genes. And in these cases, the biggest advantage of the new technology is its speed; it can sequence a sample of DNA in a couple of hours, rather than the week or more required by most of the machines now on the market. For genetic diagnostics, physicians want results fast. The Ion Torrent machine, however, is still considered a research device; it has not yet been approved by the U.S. Food and Drug Administration for clinical use.
Yemi Adesokan, cofounder of the genomics startup Pathogenica, is using Ion Torrent’s technology to develop a test for human papilloma virus in pap smear samples. Unlike existing tests, the Ion Torrent one will be able to detect infection with multiple strains of the virus, which can be linked to an increased risk of cancer. “It works really well, particularly in terms of turnaround time,” says Adesokan.