Contacts: Ryszard
Jankowiak, (515) 294-4394
Gerald Small, (515)
294-3859
Saren Johnston, (515)
294-3474
AMES, Iowa -- Ryszard Jankowiak and Gerald Small, researchers at the U.S. Department of Energy's Ames Laboratory, have come up with an innovative, on-line technique that may one day help determine an individual's risk of getting cancer from chemical pollutants.
The scientists have combined two well-known analytical methods to create one technique that can provide more detailed information on complex biomolecular samples than either standard method can do on its own.
"The marriage of capillary electrophoresis (CE) and fluorescence line-narrowing spectroscopy (FLNS) is an exciting addition to the rapidly evolving field concerned with selective detection methods that can provide the information necessary to distinguish between structurally similar molecular compounds," says Jankowiak.
Small, who is also a distinguished professor of chemistry at Iowa State University (ISU), adds, "The first important event in the production of cancer is the damage of DNA by chemical pollutants. Our new technique provides superior analytical resolution for determining the nature of the damage that leads to mutations, which may result in cancerous cells."
The powerful technology combination, capillary electrophoresis--fluorescence line-narrowing spectroscopy (CE-FLNS), takes advantage of the ability of CE to separate minute amounts of closely related biological analytes, or compounds. The other half of the combination, FLNS, a high resolution, fluorescence-based detection method developed in Small's Ames Lab research group for analytical purposes, then makes its contribution to resolving the "molecular identity crisis." FLNS characterizes the CE-separated molecular samples, further distinguishing between structurally related analytes by laser exciting them to fluoresce and emit fluorescence line-narrowed spectra.
Fundamental to the CE-FLNS technique is Jankowiak's and Small's unique capillary cryostat that encloses the capillary housing the CE-separated analytes. The capillary cryostat unites the CE and FLNS methods, cooling the analytes for FLNS characterization. Gases and vapors are removed from the outer portion of the cryostat, and inlet and return lines introduce and circulate cryogenic liquids. A continuous flow of liquid helium runs through the cryostat, cooling the centrally positioned capillary and CE-separated molecular analytes to 4.2K (-450 F) in less than one minute. The capillary cryostat and the capillary move automatically in the direction of the capillary axis, allowing the frozen and stationary analytes to be sequentially characterized by FLNS as the capillary passes through the laser-excitation region.
The CE-FLNS technique has been successfully used to identify byproducts in various tissues and urine that result from the chemistry between cellular DNA and cancer-producing pollutants, such as those found in cigarette smoke. The identification of these byproducts, called DNA adducts, is key to understanding the pathways cancer-producing pollutants take for their attack on DNA.
"CE-FLNS makes such research easier and misidentification of analytes far less likely," says Jankowiak. "It's on-line capability is especially important when dealing with minute quantities of biological materials."
The patent-pending CE-FLNS technology is available for licensing and is being investigated by several companies. At this time, the new technique has only been used for research on cancer caused by chemicals, but Small and Jankowiak expect it will find applications in other areas of biological research, as well as forensics.
Looking to the future, Jankowiak and Small are already investigating ways to enhance the CE-FLNS technology. "Versatility of our basic concept can be increased by coupling FLNS with other separation techniques," says Jankowiak.
Ames Laboratory is operated for the DOE by ISU. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and the synthesis and study of new materials.
Release date: Feb. 26, 1998
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Last revision: 4/17/98 sd