New Chemical Technology Can Detect Cancer

New chemical technology can be used to pinpoint the boundaries of tumors, detect cancer in human livers, identify disease biomarkers in urine, and recognize explosive residues on luggage.

Researchers at Purdue University (West Lafayette, IN, USA) have reviewed the technology, called desorption electro spray ionization (DESI), and related techniques in the March 17, 2006, issue of Science. The technology has made it possible to speed up and simplify the use of a mass spectrometer, an analytic device that has been long established in modern laboratories. The Purdue group has modified the technology to make it faster, more versatile, and more portable.

Conventional mass spectrometers analyze samples that are prepared and placed in a vacuum chamber. The DESI innovation is that the ionization step is performed in the air or on surfaces outside the vacuum chamber. The procedure involves spraying water in the presence of an electric field. The water molecules become positively charged and an extra proton is transferred from them to the molecules in the sample, turning them into ions. The ionized molecules are transferred to the spectrometer where the masses of ions are measured and the material analyzed.

DESI promises to be an important high-throughput tool in metablomics, the search for biomarkers, which are early signs of disease. They can be difficult to distinguish from the hundreds of chemicals present in urine, blood, and serum of healthy people. DESI allows testing to take place without separating the compounds of interest from biologic fluids. Using a two-step procedure, known as tandem step spectrometry, the presence of hundreds of components in a urine sample can be confirmed.

DESI is being commercialized by Inproteo and Prosolia (both in Indianapolis, IN, USA).



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