Biochips can hasten speed and accuracy of diagnosis
Cutting the guesswork: In future, this technology will be in every doctor's office
by Corbin Andrews National Post Wednesday, February 10, 1999
Scientists in England have used microarray technology to locate a gene that causes an insulin resistance in rats, creating hope that microarrays will soon be standard procedure in diagnosing human
illness.
A microarray is a biochip made from glass or the mineral silica. Single strands of DNA can be pasted on the chips to allow researchers and doctors to process information about a person's complete genetic makeup. Using the chip, a doctor may be able to diagnose a patient's illness in a few hours -- a process that currently takes several years. Experts believe the microarray biochips will do for biology what microprocessors did for personal computing.
By taking a simple blood sample, a doctor or researcher can extract
the patient's DNA and place it on a microarray. The portions of the DNA that the scientist wants to analyze are treated with a fluorescent dye. The chip is then processed through a scanning machine that locates the dyed sections and analyzes it, in the process, locating genetic code that is diseased or that may provide a marker for trouble in the future.
Advocates claim that microarray technology will make it as easy for
doctors to diagnose disease as it is for an auto mechanic to determine why a car won't start.
Researchers at the Medical Research Council's Clinical Sciences Centre at Hammersmith Hospital in London recently published their findings in the journal Nature Genetics.
"This technology allows us to synthesize thousands of DNA sequences on a chip about the size of a fingernail," says Ed Hurwitz of Affymetrix Inc., the California company that pioneered the microarray technology. "It is already used by most major pharmaceutical companies to research new drugs. But it's conceivably simple enough to be standard equipment in hospitals and doctor's offices."
Although commercially available since late 1997, pharmaceutical companies were the only ones to take advantage of the microarray
technology, Mr. Hurwitz says.
"Right now, microarrays are almost entirely being used for drug
discovery, but this is not where the real volume applications are,"
says Don MacAdam, president and chief executive of Toronto-based Tm Bioscience, a company that supplies ancillary technologies to Affymetrix.
Mr. MacAdam envisions a world in which microarray technology is a standard feature in every doctor's office, allowing physicians to run full-scale diagnostic tests on patients.
"Imagine that you go to a doctor with a high fever, and he tells you
that you have a cold. He's usually just guessing. You could have the
Ebola and be dead in 48 hours. Now imagine the same doctor with
microarray technology. He can run a complete check on you, and know almost instantly what you are sick from. Up till now, we've mostly been guessing, but for the first time we can know for sure."
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