Frontlines | The Sounds of Science
Courtesy of Nina Seiler
What's the sound of two molecules touching? Ask James La Clair and Michael Burkart, two University of California, San Diego, scientists, who recently developed a biosensor on the surface of an ordinary compact disc. Data from a CD is nothing more than a stream of 1s and 0s, the digital representation of how laser light reflects off the disc's aluminum platter. Any dust or scratch on the CD's surface produces errors in the playback; La Clair reasoned that biomolecules would do so as well.
After experimenting with music CDs, the team turned to data CDs. They assigned a string of bytes to represent each ligand (they used biotin and mannose), and then burned those bytes onto the disc. The data's geographical location guided an inkjet printer, which coated the disc's appropriate region with the molecules. The disc was then mixed with sample, washed, and played; errors in the data stream represented molecular interactions. "The molecules can actually act as if they're Mozart" by changing the resulting notes, says La Clair. Click to hear an audio file before (438K) and after (436K) ligand binding
Burkart and La Clair say they're not out to dethrone microarray technology; their printing resolution is inferior, and the CDs have fewer features. But, because CD players are ubiquitous, and cheap, they see a future in next-generation home diagnostics, such as high-tech pregnancy tests.
--Jeffrey M. Perkel