February 8, 2008

New Device Allows For Instant Analysis

A team of researchers at George Washington University said they have created a new detector that combines a laser with a mass spectrometer to provide instant analysis.

"We are talking about less than a second for an analysis," Akos Vertes, a professor of biochemistry and molecular biology at George Washington University, told Reuters.

The device, being called laser ablation electrospray ionization or LAESI, is the first of its kind. It works by using a laser to vaporize tiny samples which the spectrometer can then analyze. The team said that it can be used even on living organisms.

Although it provides quick analysis, the device requires a desk-sized amount of space. Vertes said that smaller spectrometers and lasers could make it portable.

According to Reuters, the laser burns the living tissue, vaporizing some of it and sending particles up into the air in a puff. In a process called electrospray ionization, a stream of electrically charged droplets is shot at the spot, intercepting the particles and merging with some of them to make charged droplets.

The 2002 Nobel Prize in Chemistry was awarded to John Fenn for the discovery of electrospray ionization.

Vertes and graduate student Peter Nemes claim they have used LAESI to find a drug sample in urine, detect the chemical changes that accompany color changes in a living plant leaf and to find explosives residue on a dollar bill.

Vertes and Nemes said that a mass spectrometer can measure any charged particle making it possible to take a series of samples in order to analyze cell-by-cell changes.

"You can just go into the field and put your laser on the surface you want to analyze," Vertes said.

"We hope it takes us to the biomedical field. We want to go in and pop one cell open, analyze the content and go on to the next cell."

They hope that the device will allow biologists to perform such tasks as analyzing tumors as they are being removed.

"It is very important to know when the cancerous tissue ends and the healthy tissue begins." Currently surgeons send samples to a pathology lab but this system could save precious minutes, Vertes said.

He is trying to use it to see stem cells in the process of differentiating, or changing, into the various cell types that they can give rise to.

Current methods require scientists to look for one change at a time in each cell sample -- destroying the living cells in the process. "The power of this method is with a single shot we can look at 50 different metabolites," he said.

George Washington University has filed for a patent on the system.


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