IBM scientists have built a biochip-based one-step point-of-care-diagnostic test (photo) that requires less sample volume, is significantly faster, portable, easy to use, and can test for many diseases, including cardiovascular disease.
As reported in Lab on a Chip, December 2009, Volume 9, Issue 23, IBM Research - Zurich scientists Luc Gervais and Emmanuel Delamarche, in collaboration with the 
University Hospital of Basel in Switzerland, developed the test that uses capillary forces to analyze samples of serum, or blood, for the presence of disease markers. These are typically proteins that can be detected in people’s blood for diagnostic purposes. IBM explained capillary action force as the tendency of a liquid to rise in narrow tubes or to be drawn into small openings.
"This point of care test has achieved the trifecta for medical staff in that it is portable, 
fast and requires a very small volume of sample," Delamarche said in a statement. "We are giving back precious minutes to doctors so they can make informed and accurate decisions right at the time they need them most to save lives."
See also: Photos: IBM's nanoscale DNA sequencer
IBM encoded the forces of capillary action on a microfluidic chip made of a silicon compound, measuring 1x5 centimeters, and containing sets of micrometer wide channels where the test sample flows through in approximately 15 seconds.
IBM noted that 15 seconds is several times faster then traditional tests and that the filling speed can be adjusted to several minutes when the chip requires additional time to read a more complex disease marker.
The microfludic chip works off of a one microliter sample, 50 times smaller than a tear drop, that is pipetted onto the chip, where the capillary forces begin to push the sample through an intricate series of mesh structures.
IBM said the sample then passes in a region where microscopically small amounts of the detection antibody have been deposited. These antibodies have a fluorescent tag to recognize the disease marker and attach to it within the sample. Only 70 picoliters (a volume one million times smaller than a tear) of these antibodies are used, making their dissolution in the passing sample extremely fast and efficient.
In the next stage the disease marker is captured on the surface of the chamber. The tagged disease markers can be viewed using a portable sensor device that contains a chip similar to those used by digital cameras, according to IBM. Medical professionals then can visually confirm the strength of the disease marker in the sample to determine the next course of treatment.
IBM noted that due to its small size, the chip can be embedded in several types of form factors, depending on the application, including a credit card, a pen, or something similar to a pregnancy test. Besides diagnosing diseases, the test is also flexible enough to test for chemical and bio hazards, according to IBM.
Suzanne Deffree, Managing Editor, News - Electronic News