July 11, 2006 —
US and Australian scientists have pioneered a new hybrid method for
genomic sequencing that is faster and cheaper than state of the art
breakthrough will be welcomed in medical and biotechnology circles
where there is rising demand for genome-sequencing technologies. The
new hybrid method combines the best of new and old code cracking
methods for "fingerprinting" the genetic basis of life.
Institute and the University of New South Wales in Sydney, Australia
published the findings in the Proceedings of the National Academy.
the entire, genetic code of an organism is expensive and until recently
has relied in its fundamentals on a 30 year old technology that
involves a physical separation of gene fragments," says Dr Torsten
Thomas, a study co-author and senior research fellow at the University
of New South Wales.
"A newer method which has emerged in the
past year uses real-time, light-based observations of gene synthesis to
reveal genomic information. It produces genomic information up 100
times faster than the old technology."
Using the genomes of six
ocean bacteria, the scientists evaluated the utility and cost
effectiveness of the old and new methods to show that a hybrid method
was better than either method on its own. They found that combining the
advantages of the two sequencing methods in a hybrid approach produced
better quality genomic information.
The team found that the
traditional method known as ‘Sanger’ sequencing worked best at
sequencing large segments of the genomes, while the newer method known
as ‘454 pyrosequencing’ was more adept at sequencing smaller, more
difficult sections, such as unclonable regions and gaps induced by
secondary structures. The hybrid sequencing approach enabled the
scientists to more easily close sequencing gaps between genome
fragments compared with previous techniques.
suggest that the hybrid technique will become the preferred method for
sequencing small microbial genomes, as the Sanger method is more
capable of sequencing larger segments of DNA. "The new hybrid approach
has generated exceptional results for several, marine microbes and we
hope that our findings will kick-start other genome projects that were
previously constraint by economic considerations", Dr Thomas says.
Source : University of New South Wales