Faster and less expensive gene sequencing holds the promise of speeding up the discovery of cures for genetic disorders and the elimination of whole categories of diseases. To that aim, the Human Geneome Project was launched in 1990.
Walter Fiers at the University of Ghent in Belgium was the first to sequence a complete nucleotide of RNA. DNA followed in 1977 with the first genome project sequenced by Fred Sanger.
Thirty years later, the genome of DNA pioneer Dr. James Watson was successfully sequenced.
Genome sequencing lists the order of every DNA base in the target genome. The process is time-consuming and very expensive.
DNA sequencing meets nanoprocessing
The current method of sequencing a genome is a tedious and expensive process. First, the DNA is segmented and replicated. Chemicals are used to accomplish this, unfortunately, they destroy the original sample. The data is then transferred to a computer and the next segment is processed. The process on a genome of a large mammal, like a human, can take years.
Now, a team of researchers from Imperial College in London, England have developed a breakthrough nano device that may be the foundation for an entirely new technology. If it’s successful, the new approach would sequence an entire human genome in minutes and cost a mere handful of dollars.
The genome of Dr. Watson took two years to sequence at a cost of one million dollars.
Incredible nanopore
The device the scientists created is basically a 50-nanometer hole—a “nanpore”—bored through a silicon chip. It works by shooting DNA strands through the nanopore at a high velocity. The coding sequence is read utilizing a “tunneling electrode junction” as the strands emerge from the hole.
The junction, or gap, is created by separating two platinum wires 2-nanometers apart. An electrical current jumps from one wire to the other. This electrical current then reads the DNA signature of the strands’ base codes as they pass through. Each strand has a unique signature as it interacts with the current.
10 million bases a second
As the DNA is shot through like machine gun bullets, a computer logs each signature and compiles the entire sequence—theoretically in a matter of minutes.
“We haven’t tried it on a whole genome yet, but our initial experiments suggest that you could theoretically do a complete scan of the 3,165 million bases in the human genome within minutes, providing huge benefits for medical tests, or DNA profiles for police and security work,” said study co-author Dr. Joshua Edel during an interview with science website gizmag.com. “It should be significantly faster and more reliable, and would be easy to scale up to create a device with the capacity to read up to 10 million bases per second, versus the typical 10 bases per second you get with the present day single molecule real-time techniques.”
The two scientists that published the results of the experiments with the device in the journal Nano Letters claim that it’s a first. A similar device was claimed by American researchers in August of 2010, so the claim may come under dispute.
Both scientists agree that a viable commercial version of the nano gene sequencer may not be available until 2020.
“The next step will be to differentiate between different DNA samples and, ultimately, between individual bases within the DNA strand,” said study co-author Dr. Tim Albrecht. “I think we know the way forward, but it is a challenging project and we have to make many more incremental steps before our vision can be realized.”
