C&EN: TODAY'S HEADLINES - MOLECULAR SCREENING

STU BORMAN

Atechnique in which commercially available compact discs (CDs), CD players, and CD computer drives are used to monitor biomolecular interactions could lead to inexpensive molecular screening devices for lab research and for diagnostic testing in homes and doctors’ offices [Org. Biomol. Chem., published online Aug. 12, http://xlink.rsc.org/?DOI=b306391g].

UCSD PHOTOS

In the technique, a CD surface is covalently modified in specific addressable locations with ligands capable of binding selectively to proteins and other biomolecules. Sample proteins that bind to the surface cause errors in the signal that’s obtained when the CD is scanned with the laser in a conventional CD player or drive. Error analysis software is then used to identify and quantify the interactions.

Essentially, the technology creates protein microarrays on CD surfaces and uses CD players to “read” them. Potential applications include identifying proteins and testing for infectious diseases.

The methodology was devised and patented in 2000 by chemist and molecular biologist James J. La Clair of Bionic Bros GmbH, Berlin. La Clair donated the patent to the University of California, San Diego, so that he could work with assistant professor of chemistry and biochemistry Michael D. Burkart to develop the technology.

Techniques currently used to detect molecular interactions on protein microarrays include fluorescence spectroscopy and mass spectrometry—instrumentation that is generally expensive. “A protein chip fluorescent reader can cost $100,000,” Burkart says, whereas the CD drive he and La Clair used in their experiments cost about $25.

CD-based monitoring is not new. For example, Burstein Technologies, Irvine, Calif., is developing a system of CDs and slightly modified CD readers for clinical diagnostics, biowarfare agent detection, DNA tests, and food and water tests. And Gyros AB, Uppsala, Sweden, is developing CD-based microlaboratory systems for a range of similar tests.

But Burkart notes that the UCSD system is the first to be based on store-bought CD players and drives. “Our hope is that eventually we could make available technology that’s easy to use and attainable for labs that don’t have very large budgets,” he says. “In theory, anyone who has a computer with a CD drive could do medical tests in their own home,” La Clair adds.

The scientists hope other researchers will be interested in customizing the technology for a range of applications. “We plan to make this fully available and see what people come up with,” Burkart says.

In addition to using errors in digital data to analyze molecular interactions on the CD surface, one can also use errors in sound, the researchers note. “How many people on this planet can actually hear a molecule attached to another molecule?” La Clair asks.