UCSD scientists develop novel way to screen...( of a CD we identified proteins adherin...)

While usually anything, like a scratch on the CD surface, that would interfere with the detection of the bits of information encoded on a CD would be a drawback, the UCSD researchers actually exploited this error to detect molecules.

"That's the novelty of this," Burkart points out. "We are actually using the error to get our effect."

The typical CD consists of a layer of metal sandwiched between a layer of plastic and a protective lacquer coating. When a CD is burned, a laser creates pits in the metal layer. A CD player uses a laser to translate the series of pits and intervening smooth surface into the corresponding zeros and ones that make up the bits of digital information.

To do molecular screening, the researchers took a CD encoded with digital data, and enhanced the chemical reactivity of the plastic on the readable surface. They then added molecules they wanted to attach to this surface to the empty ink wells of an inkjet printer cartridge and used the printer to "print" the molecules onto the CD. This resulted in a CD with molecules bound to its readable surface in specific locations relative to the pits in the metal layer of the CD encoding the digital information. When the CD with these molecules attached is placed in a CD player, the laser detects a small error in the digital code relative to what is read from the CD without the molecules attached.

To detect proteins or other large molecules in a solution like a blood sample, the modified CD is allowed to react with the sample solution. Like a key that only fits in a certain lock, some proteins bind to specific target molecules. Thus, specific molecules on the surface of a CD can be used to "go fishing" for certain proteins in a sample. The attachment of these proteins will introduce further errors into the reading of the CD
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Contact: Sherry Seethaler
sseethaler@ucsd.edu
858-534-4656
University of California - San Diego
18-Aug-2003