September 1, 2008 Chemists and immunologists devised a new rapid system for detecting and identifying viruses. It uses surface enhanced Raman spectroscopy to measure the frequency of near-infrared laser light as it scatters off viral DNA and RNA. After a swab of a person's nasal passage, the technique can detect individual virus particles quickly and identify many types.
We've all heard about the threat of a pandemic. Scientists say during a major disease outbreak, or even a bioterrorism attack, one of the biggest enemies could be time. Using traditional testing, it can take days -- even weeks -- to confirm a diagnosis and isolate those infected. Now, science may have found a way to speed up the clock.
Every day, millions of people travel in and out of U.S. airports from cities all over the world; and they're bringing more with them than just their baggage -- they're bringing germs.
"If you really sit and think about it, it's a lot to be concerned about because everything is spreading so fast these days," says one concerned airline traveler. Airports already screen your bags. Now, University of Georgia scientists have developed a system that could one day screen you -- for disease. Researchers say the rapid response system can detect viruses from a nasal swab in one minute or less.
"We can detect within 30 seconds -- 30 to 60 seconds -- the molecular fingerprint of a virus or bacteria based on its nucleic acid sequence," says Ralph Tripp, Ph.D., a viral immunologist for the Department of Infectious Diseases at the University of Georgia.
The virus is exposed to a laser light which highlights the virus' unique molecular "fingerprint." Knowing this "fingerprint" helps viral immunologists identify the virus.
"Absolutely, yeah, these are fingerprints of individual viruses," says Jeremy Driskell, Ph.D., an analytical chemist at the University of Georgia.
Chemists say the technique is so powerful, it can detect even a single virus particle in seconds and identify countless mutations -- whether it's flu, rotavirus or something else. They're already developing a laptop-sized testing station for airport screening.
"It'll provide you with a red light, green light effect saying yes, this person has or has not the virus that you're looking at," Dr. Tripp says.
For disease outbreaks and bioterrorism, or simply speeding up a doctor's diagnosis, researchers say this new technique could one day be an important weapon in the fight against disease.
WHAT IS A VIRUS? Unlike bacteria, viruses are not cells; they consist of DNA or RNA molecules, containing the virus's genes, surrounded by a protein coat. A virus can attach itself to cells and inject molecules into the cell, or the cell may absorb it. Once inside, the molecules cause the infected cell to make new viruses that can spread to other cells.
WHAT IS SPECTROSCOPY? Spectroscopy is a technique often used by astronomers and physicists to study the make-up of an object based on the light it emits. In this case it is used to identify the scattering of light off of the DNA and RNA within viruses. This is possible because each chemical element has a unique signature, emitting or absorbing radiation at specific wavelengths. For example, sodium, used in street lights, emits primarily orange light. Oxygen, used in neon lights, emits green light. By passing the light from a star or other object through a special instrument, called a spectrograph, the light is "spread" into a spectrum in much the same way visible light is spread into its colors by a prism. By carefully studying how the spectrum becomes brighter or darker at each wavelength, scientists can tell what chemical elements are present.
The Optical Society of America contributed to this report. This report has also been produced thanks to a generous grant from the Camille and Henry Dreyfus Foundation, Inc.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.