CAMBRIDGE, Mass.--MIT researchers have created an inexpensive method to screen for millions of different biomolecules (DNA, proteins, etc.) in a single sample-a technology that could make possible the development of low-cost clinical bedside diagnostics.

The work, based on tiny customizable particles, could also be used for disease monitoring, drug discovery or genetic profiling. Even though the particles are thinner than the width of a human hair, each is equipped with a barcoded ID and one or more probe regions that turn fluorescent when they detect specific targets in a test sample.

Using a new, extremely versatile technique, the researchers can produce a "virtually unlimited" array of particles to test for DNA, RNA, proteins and other biomolecules, said Daniel Pregibon, a graduate student in chemical engineering at MIT.

Pregibon is the lead author of a paper on the work that will appear in the March 9 issue of Science.

He and co-author Patrick Doyle, the Doherty Associate Professor of Chemical Engineering, believe their particles could become an effective and inexpensive way to perform medical diagnostic tests at a patient's bedside.

Current testing methods are cost-prohibitive for bedside use, Pregibon said. The MIT particles are inexpensive to manufacture, and their results are as accurate, if not more so, than the results from more expensive systems, he said.

The particles offer a new way to do "multiplexed detection"-testing a single sample for multiple targets. In the laboratory, a common (but expensive) multiplexing technique involves a planar microarray-a flat surface with many spotted probes that each test for different targets. The MIT researchers are taking this approach away from planar surfaces onto free-floating particles.

With the tiny particles, it is much easier to custom-design each biological test, said Doyle. "It's very easy to tailor what you give a customer. You could
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Contact: Elizabeth Thomson
thomson@mit.edu
617-258-5402
Massachusetts Institute of Technology
8-Mar-2007