AMES, Iowa, Mar 23, 2001 (United Press International via COMTEX) -- Researchers are developing a new biosensor that could someday allow doctors to detect early indicators of cancer with a simple, inexpensive urine test.

Researchers at the U.S. Department of Energy's Ames Laboratory in Ames, Iowa, have created a biosensor technology that works by mounting antibodies (proteins that fight foreign agents and infection in the body) to a gold chip that is then exposed to a urine sample. Depending on their design, the antibodies bind to disease indicators known as adducts. When scientists then apply a laser to the chip at very low temperatures, the adducts, if present, begin to emit light. "This technology essentially could give us an effective way to perform precancer diagnosis for a range of cancers," Professor Ryszard Jankowiak, a senior scientist at Ames, told United Press International in a telephone interview.

"With advances in genetics and our increased knowledge about the origin of disease, we now need to exploit that information to screen for disease indicators," said Marc Porter, a project contributor and chemistry professor at Iowa State University. "This is basically a development to achieve that goal."

Jankowiak said that while the technology is still far from being commercially available, he is working to design antibodies that detect the beginnings of prostate and breast cancer. Early on researchers were unable to detect the florescent adducts at room temperature. But when they added a thin glycerol layer to the chip's surface and lowered the temperature while scanning with the laser, the adducts' emissions became visible. The low temperature -- 452 degrees Fahrenheit--causes the sought after molecules to slow down, making them more easily detectable, enhancing their florescent intensity by a factor of 10, Jankowiak said. The technology could eventually be used to monitor electronic circuits, enhance environmental restoration and boost basic scientific research. In the shorter term, it might offer an affordable means to test for a common carcinogen known as hydrocarbon benzopyrene or BP, said Porter.

A technique known as CE-fluorescence line narrowing spectroscopy (CE-FLNS) is the primary means for detecting BP in the body but is prohibitively expensive, especially for routine use in developing nations.

"A persistent problem with biosensors is that they are incompatible, they fowl up or get attacked," Edward F. Leonard, professor of chemical and biomedical engineering at Columbia University in New York told UPI. "These researchers seemed to have aimed at an easier target, namely they don't have to deal with the body's environment because their sensors are used externally."

"In developing this device further, they will face two major considerations, a biological and a physical one. The biological part is finding the right antibodies and the physical part is making sure they interact with DNA in a way produces a detectable change. There are many people trying to do the same thing, it's just an issue of whether or not their device can prove to be more sensitive than anyone else's."

(Reported by Technology Writer Kelly Hearn in Washington)

Copyright 2001 by United Press International.

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