London: British scientists claim to be developing a new technology which could ultimately sequence a person`s genome in mere minutes, at a fraction of the cost of
current commercial techniques.
A team at Imperial College London has already patented an early prototype technology which they believe could lead to an ultrafast commercial DNA sequencing tool within ten years, the `Nano Letters journal reported.
The research suggests that researchers could eventually sequence an entire genome in a single laboratory procedure, whereas at present it can only be sequenced after being broken into pieces in a highly complex and time-consuming process.
Fast and inexpensive genome sequencing could allow ordinary people to unlock the secrets of their own DNA, revealing their personal susceptibility to diseases such as Alzheimer`s, diabetes and cancer, say the scientists.
Dr Joshua Edel, one of the authors on the study from the Department of Chemistry at Imperial College London, said: "Compared with current technology, this device could lead to much cheaper sequencing: Just a few dollars, compared with one million pound to sequence an entire genome in 2007.
"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.
"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."
In their research, the team demonstrated that it is possible to propel a DNA strand at high speed through a tiny 50 nanometre hole -- or nanopore -- cut in a silicon chip, using an electrical charge.
As the strand emerges from the back of the chip, its coding sequence (bases A, C, T or G) is read by a `tunnelling electrode junction`. This 2 nm gap between two wires supports an electrical current that interacts with the distinct electrical signal from each base code.
A powerful computer can then interpret the base code`s signal to construct the genome sequence, making it possible to combine all these well-documented techniques for the first time, say the scientists.
The study`s co-author Dr Emanuele Instuli added: "Getting the DNA strand through the nanopore is a bit like sucking up spaghetti. Until now it has been difficult to precisely align the junction and the nanopore.
"Furthermore, engineering the electrode wires with such dimensions approaches the atomic scale and is effectively at the limit of existing instrumentation. However in this experiment we were able to make two tiny platinum wires into an electrode junction with a gap sufficiently small to allow the electron current to flow between them."