Here's Why

Print, spit, and play

A team at the University of California, San Diego have developed a cheap way of testing blood or other biological samples for particular proteins and eventually even genes. At present, the machines to identify molecules in biological samples cost hundreds of thousands of dollars. When CD's are played on a computer CD drive, the computer automatically notes the errors, which are normally thought of as a bad thing. In this system, you inkjet print an alcohol-based mixture of protein receptors onto the CD from a regular printer with a special cartridge. You dunk it in the biological sample, clean it, and then play it on the computer. The computer counts an error every time a protein molecule binds to the surface and blocks the laser in the CD drive. These protein molecules are glued to the surface, so they don't wash off when you clean the disk. You can literally hear the molecules, as they've tried playing music CDs to hear the errors. For example they were able to detect an enzyme that turns starch into sugar. They had someone spit onto a receptor-printed CD of Beethoven's Fifth symphony, clean it up, and then listen for the differences in the music. This is a little like the artists who grow fungus on their music CDs and photo CDs and then play them for the groovy results of lasers being diffracted by fungus microfibres growing from spilt beer. For more accurate readings the team have developed software to run on linux home PCs, comparing the errors and bytes on the CD before and after exposure to a biological sample. They plan to release the software as open source free to download from the net, so that anybody can play with it.

About the author: Ian Woolf lives in Sydney, has a degree in Applied Science, worked as a solar astronomer, software engineer, systems programmer, webmaster, research assistant, Cisco CCNA tutor, Physics laboratory demonstrator, Computational Theory lecturer, and subject coordinator; while changing his career to freelance writing and broadcasting. Listen to Ian on the Diffusion radio science show on radio 2SER 107.3FM Monday at 6:30pm in Sydney or streaming audio on www.2ser.com, or listen to the Diffusion podcasts. You should follow me on twitter, here

Posted by iwoolf at July 22, 2005 7:59 PM