Biochip-based test aims at speedy disease diagnosis

IBM scientists have built a biochip-based, one-step point-of-care diagnostic test that requires less sample volume and is significantly faster than currently available techniques. An article in the December 2009 issue of Lab on a Chip describes the research. The portable, easy-to-use system can test for many diseases, including cardiovascular disease. IBM Research-Zurich scientists Luc Gervais and Emmanuel Delamarche, in collaboration with the University Hospital of Basel in Switzerland, developed the test, which uses capillary forces to analyze samples of serum, or blood, for the presence of disease markers. Capillary-action force is the tendency of a liquid to rise in narrow tubes or to be drawn into small openings.

IBM encoded the forces of capillary action on a microfluidic chip made of a silicon compound, measuring 135 cm and containing sets of micronwide channels in which the test sample flows through in approximately 15 sec—several times faster than traditional tests. Further, you can adjust the filling speed to several minutes when the chip requires additional time to read a more complex disease marker.

The microfluidic chip works with a 1µl sample—50 times smaller than a teardrop—that the researchers move onto the chip using a pipette. The capillary forces then begin to push the sample through an intricate series of mesh structures. The sample passes into a region into which researchers have deposited microscopic amounts of the detection antibody. The test uses only 70pl—1 million times smaller than a teardrop—of these antibodies, making for their fast and efficient dissolution in the passing sample.

IBM

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A biochip-based diagnostic test requires less sample volume than other techniques.