Team prototypes instant genome test

Scientists from Imperial College London have prototyped a tool that they say could ultimately sequence a person’s genome in minutes, at a fraction of the cost of current techniques.

The research suggests that within ten years scientists could sequence an entire genome in a single lab procedure. This could give ordinary people an indication of their personal susceptibility to diseases such as Alzheimer’s, diabetes and cancer.

“Compared with current technology, this device could lead to much cheaper sequencing: just a few dollars, compared with $1 million to sequence an entire genome in 2007,” said Dr Joshua Edel from the Department of Chemistry.

“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.”

The researchers were able 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 2nm 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.

“The next step will be to differentiate between different DNA samples and, ultimately, between individual bases within the DNA strand – ie true sequencing,” said Dr Tim Albrecht from the Department of Chemistry.

“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 realised.”