ID :
94079
Thu, 12/10/2009 - 08:37
Auther :
Shortlink :
http://m.oananews.org//node/94079
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New way to confirm meningococcal
AAP - An Australian scientist has developed a new diagnostic technique that could be used to quickly confirm the presence of dangerous meningococcal bacteria.
The technique, which relies on the strange properties of gold "nanoparticles", can
flag the presence of the bacteria's DNA in minutes while conventional methods can
take hours if not days.
"It depends on how much of the DNA is present but you can see a change in colour in
about 15 minutes," said Dr Sapna Thoduka, who developed the technique as part of her
PHD studies at Melbourne's RMIT University.
"(Otherwise) the best way of finding out if someone has meningococcal disease is
through culture, and that takes a few days because it is a slow growing bacteria."
A meningococcal infection can be fatal, but the bugs can be killed off in about 24
hours with antibiotics.
The bacteria can infect the lining of the brain and spinal cord (meningitis) or the
blood (septicaemia) but they can also infect joints, the eyes or cause pneumonia.
Early diagnosis is the key as, even with appropriate treatment, a meningococcal
infection can lead to severe complications.
Dr Thoduka's new technique uses the unique properties that gold atoms are known to
have when a few of them cluster together to form a nanoparticle.
The properties:
- Suspend these nanoparticles, each about a thousand times thinner than a human
hair, in liquid and they appear to be bright red in colour;
- Cause these nanoparticles to become more closely clumped together, then they
appear to change colour.
"I put DNA probes onto the nanoparticles," Dr Thoduka said.
"... And when they were in the presence of meningococcal DNA it brought the
particles closer together, and it changed the colour of the solution from red to
blue."
These probes were matched, like a key in lock, to react only to the genetic profile
of the meningococcal bacteria.
But Dr Thoduka said the same technique could be used to create a range of different
DNA-based tests, including a test that would raise a red flag if human DNA had
traits that indicated genetic disease.
Dr Thoduka's project was supported by Nanotechnology Victoria.
"In the future, this will hopefully lead to more rapid detection of meningococcal
disease and earlier treatment, which will ultimately result in fewer deaths and less
severe complications," she also said.
The technique, which relies on the strange properties of gold "nanoparticles", can
flag the presence of the bacteria's DNA in minutes while conventional methods can
take hours if not days.
"It depends on how much of the DNA is present but you can see a change in colour in
about 15 minutes," said Dr Sapna Thoduka, who developed the technique as part of her
PHD studies at Melbourne's RMIT University.
"(Otherwise) the best way of finding out if someone has meningococcal disease is
through culture, and that takes a few days because it is a slow growing bacteria."
A meningococcal infection can be fatal, but the bugs can be killed off in about 24
hours with antibiotics.
The bacteria can infect the lining of the brain and spinal cord (meningitis) or the
blood (septicaemia) but they can also infect joints, the eyes or cause pneumonia.
Early diagnosis is the key as, even with appropriate treatment, a meningococcal
infection can lead to severe complications.
Dr Thoduka's new technique uses the unique properties that gold atoms are known to
have when a few of them cluster together to form a nanoparticle.
The properties:
- Suspend these nanoparticles, each about a thousand times thinner than a human
hair, in liquid and they appear to be bright red in colour;
- Cause these nanoparticles to become more closely clumped together, then they
appear to change colour.
"I put DNA probes onto the nanoparticles," Dr Thoduka said.
"... And when they were in the presence of meningococcal DNA it brought the
particles closer together, and it changed the colour of the solution from red to
blue."
These probes were matched, like a key in lock, to react only to the genetic profile
of the meningococcal bacteria.
But Dr Thoduka said the same technique could be used to create a range of different
DNA-based tests, including a test that would raise a red flag if human DNA had
traits that indicated genetic disease.
Dr Thoduka's project was supported by Nanotechnology Victoria.
"In the future, this will hopefully lead to more rapid detection of meningococcal
disease and earlier treatment, which will ultimately result in fewer deaths and less
severe complications," she also said.
