The output from an automated DNA sequencing machine used by the Human Genome Project to determine the complete human DNA sequence. Image courtesy of The Sanger Institute, Wellcome Images.
Sequencing your DNA just got a little cheaper. In the pursuit of a $1,000 human genome, Jonathan Rothberg invented a new genome sequencing machine. The machine decodes the DNA directly onto the chip and detects volt changes, rather than light, which other sequencing methods use. By utilizing semiconductors in sequencing genomes, Moore’s Law (which states that the number of transistors that can be placed inexpensively on a chip will double approximately every two years) will be utilized to bring down the price over the next few decades. (Fittingly, Rothberg recently sequenced the genome of Intel co-founder and Moore's Law namesake Gordon Moore.)
A recent New York Times article outlines the high—but slowly decreasing—costs of genomic sequencing. One particular example given is the genome of Harvard Medical School’s George Church. Church, a CHF oral history interviewee, has a long history in the field: in 1984 he and Walter Gilbert developed the first direct method for genomic sequencing. In his interview, he speaks about the development of that method:
To do that, I had to extract the entire genome, and mess with the whole genome. And I started thinking about it. I said, “Wow, I just did a reaction on an entire genome. You know, I can’t access it all at once, but I can access anyplace I want in it." ... It was like RAM; I can go in and I can get anything.
Accessing the entire genome can have tremendous benefits for research—as it did for Church—and its possibilities are growing with improvements like Rothberg’s. Few human genomes have been completely decoded, but costs have dropped significantly over the past several years as technology has improved. (In 2008, sequencing the DNA of James Watson, co-discoverer of DNA’s structure, cost approximately $5.7 million.) A much-discussed goal is $1,000 per human genome.
Why the race toward a $1,000 genome? Making sequencing cheaper and faster has several benefits. One such benefit is the possibility of adding genome sequencing to the battery of routine medical tests. And cheaper sequencing means the costs for researchers to use the information would be more manageable. What’s more, a sequenced genome by itself is not necessarily very useful, but thousands of them could be: complex diseases such as diabetes or cancer are not necessarily caused by one gene variant, but rather a larger, unknown group of rare variants. With so few genomes decoded, understanding the causes of complex diseases is currently impossible.
Church has spent the past 30 years as a participant and leader in the push for cheaper, effective ways to sequence genomes, as well as a voice in how these genomes might be used. He also points out that the decreasing costs of sequencing genomes could allow for a better dialogue between patients, practitioners, and researchers: “Research subjects should be able to participate; they shouldn’t just be objects that are objectified and be identified and left out of the dialogue … They should have access to their own data.”
As technology continues to improve, it is the hope of many in the field that sequencing many more genomes will uncover the currently encoded information about diseases and other medical issues inside the RAM of the human body—something worth infinitely more than $1,000.
Genomes for Sale [Periodic Tabloid]
The Human Genome Turns Ten [Periodic Tabloid]