Next, as with other approaches, Complete Genomics determines the sequence of the target DNA using a series of fluorescently labeled DNA strands designed to bind to corresponding letters. But while advanced sequencing technologies currently in use--including those from Illumina, Applied Biosystems, and 454--read the sequence sequentially, letter by letter, Complete Genomics's labels bind to the target DNA randomly. Both the labels and the DNA circle are designed to allow scientists to deduce the position of each highlighted base--information that is then used to computationally reconstruct the sequence of the target DNA. (With both Complete Genomics's and other companies' methods, the short strands are computationally stitched together to generate the entire genome sequence.)
Because the identification of each base in the sequence does not depend on the correct identification of the previous one, individual errors have less impact on the overall result, generating a more accurate sequence with less repeat sequencing. (For a more detailed explanation and schematic of Complete Genomics's sequencing process, click here.)
Beyond its unique technology, Complete Genomics has also chosen an unusual business model: rather than selling instruments, as most sequencing companies have done, it plans to offer sequencing services through a commercial-scale genome center. Cliff Reid, the company's president and chief executive officer, hopes that both the service model and the price tag will appeal to those who don't want to do their own sequencing, such as pharmaceutical companies. "They don't want to purchase an instrument; they want to purchase data," says Reid. In an effort to further pharmacogenomics--the ability to prescribe the right drug at the right dose to a patient based on his or her individual genetic profile--genomics is a growing component of clinical trials.
The company is now building a massive data center to manage the immense volume of information it expects to generate; it's planning to have a computer cluster containing 60,000 processors online by 2010. "No one has ever put together a data processing center this size for sequencing--because no one has ever been able to sequence this many genomes," says Reid. Complete Genomics will focus entirely on human-genome sequencing, unlike other companies, which use their technology for a variety of sequencing projects. And unlike Knome, a personal-genomics startup that offers individuals a complete genome sequence and personalized analysis for $350,000, Complete Genomics provides only the genome sequence.