Artist's impression of the DNA double helix. A fast, low-cost new technique for genome sequencing could pave the way to personalised medicine.

Credit: Michael Ströck

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PARIS: The idea of having your personal genetic code unravelled was once a dream reserved for people who were fans of science and had deep pockets – but not for long, scientists say.

A new technique, described today in the British journal Nature, has slashed the cost and time of genome sequencing, in an important step towards tailor-made medicine.

The human genome comprises around three billion base pairs – the 'rungs' in the ladder of the chemical code for life.

The Human Genome Project, a consortium of public-sector scientists, spent US$437 million dollars (AU$466 million) and took 13 years to complete the first sequencing of a genome, in 2003.

It tied in a race against maverick biologist Craig Venter, who developed a fast-track sequencing method. Later, Venter's own genome was sequenced in a project - completed last September - that cost around US$100 million dollars.

Cheap and easy

Now a team led by the Rothberg Institute for Childhood Diseases Research in Connecticut, USA, has used a next-generation technique to sequence a sample given by James Watson, the Nobel laureate who co-discovered the DNA double helix.

The technique dispenses with the laborious and costly cloning of the sample by bacteria, which is the precursor to the traditional sequencing method. Instead, the sample is directly amplified by a process called polymerase chain reaction.

The long string of 'rungs' is then broken up and unravelled by parallel sequencers, and the resulting data is fed into a powerful computer for reassembly and analysis.

In all, sequencing Watson's genome cost less than US$1 million dollars and the project took a mere two months to complete. This fast, low-cost approach "is an important milestone in our ability to connect 'personalised genomes' to 'personalised medicine'," according to the paper's authors.

Tailor-made medicine

Biologists are working hard on deciphering the code, seeking to identify flawed genes that might pass on inherited disease or expose an individual to enhanced risk of cancer, smoking addiction, obesity or alcoholism, for instance.

In the future, the researchers hope low-cost sequencing techniques might allow the tailoring of medicine to suit an individual's genome, to maximise the benefits of treatment and minimise side-effects.