Analyzing Small Fluid Samples

Microfluidics is a technology or approach that utilizes or studies small fluid samples. Generally, microfluidics involves manipulating the sample in channels that measure only tens of millimeters across. This technology is present on a chip – a form that has become commonplace in recent decades thanks to silicon chips and semiconductors in the computer and information sciences and the gene microarrays used in genetic and microbiological studies.

A common problem with biological samples is volume – the less blood needed to run a test, the more comfortable it is for the patient and the less time and work involved. Fast and reliable results are desirable for everyone involved. Another advance from this technological field is a reduction of cost by mass producing individual, disposable chips with fewer components and smaller size that can be used at the bedside or home to replace expensive, involved tests that require manpower, equipment, and sample storage (FuturePundit).  One example of a current application of this methodology is the blood glucose meters used every day by diabetes patients at home and doctors and nurses in clinical and hospital settings (IVDTechnology).

In 2008, researchers from Caltech and the Institute for Systems Biology (Seattle) announced that they had developed a microfluidics based blood test chip that would allow doctors to monitor the disease state and cancer risk of patients – a 10-minute test with a single drop of blood replacing many hours of work by several technicians.  Current testing costs approximately $500 a protein and requires 10 to 15 milliliters of blood. The chip will cost approximately 5 cents a protein. The chip will be developed and marketed by Integrated Diagnostics, which was formed in 2009 and secured additional funding in 2010 to push forward with the progress being made on the proteomics chip (MarketWire).

Essentially, the chip separates the blood sample applied to it to direct the protein-rich serum into channels coated with protein-capturing bar codes that light up under a fluorescent microscope if the blood contained the protein it captures (TechnologyReview). The bar codes are DNA-bound antibodies that bind to specific proteins. The presence of a bound protein appears red, while a green control line allows a technician to know the test received sample.

The proteomics 10-minute blood test chip could be designed to test for various proteins at once, or specific sets of proteins. Many seem to believe that it would allow cancer markers, inflammatory states in chronic disease, and known issues that develop with age to be easily monitored at doctor visits or at home. No availability date has been set as work is ongoing. One of the researchers behind the chip, Leroy Hood, is credited with developing rapid DNA sequencers, boosting confidence that this technology will be brought to fruition.

The original paper on this microfluidics application was published in the journal Nature Biotechnology November 16, 2008 (link).