Mars Bar-sized device can decode your DNA

Finding out what nasty bugs are in your system could soon be done much faster thanks to a Mars Bar-sized device capable of quickly decoding your genetic make-up.

Dr David Eccles tests a miniature DNA sequencer called MinION, which in just a few hours can analyse a portion of our own personal DNA. Photo / Malaghan Institute

The Wellington-based Malaghan Institute has been testing a miniature DNA sequencer called MinION, which in just a few hours can analyse a portion of our own personal DNA.

Even just a decade ago, this took more than a decade, required huge machines and cost billions of dollars.
Soon, the sequencing time will become even faster -- about 20 times in fact -- when the institute receives upgraded software from designers Oxford Nanopore Technologies.
One of the scientists using it, bioinformatician Dr David Eccles, sees a future, perhaps just a few years away, where these devices will be used by doctors to check a throat swab for viral or bacterial infections in the same time it would take to carry out a brief blood test.

This would mean GPs could quickly prescribe a patient with an antibiotic specific to their infection, rather than a broad-spectrum drug which might not be as effective.
The device has been specifically used by the institute to sequence and compare different mitochondrial genomes, which are small compared with the full human genome sequence.
Sequencing mitochondrial genomes can be done much faster as scientists only have to work with around 16,300 "bases", or nucleotides that are measurable sub-units of the DNA.
The MinION works by reading off the genetic sequences from a DNA sample as it travels through about 500 tiny pores in the device, with the data fed into a laptop it is attached to via USB.
Naturally, these DNA bases will try to fly through at a rate of a million per second, but a specially-designed protein in the device slows this down to a rate of just 30 bases per second.
The new and improved technology will enable the device to do just the same job, but with a faster processing rate of around 600 bases per second.
Dr Eccles expected the cost of sequencing the entire human genome, along with all other associated lab work, would soon be only around $1000 per sample.
Malaghan scientists are now using it to study the genome of a hookworm-like parasite, in order to find proteins that could help treat the one billion people who are infected with hookworm around the world.
"The MinION is also the only sequencer that has been able to be used on-site for Ebola virus sequencing, and would be of great use in future outbreaks of unknown viral diseases."