IBM (Zurich) has leveraged its experience in microelectronics to develop a point-of-care (POC) lab-on-a-chip tool that requires a blood or serum sample that's 50 times smaller than a tear drop and can produce test results in minutes for a wide range of diseases from cardiovascular to cancer.

"We've made a device that's easy to use by non-trained personnel and we envision it to have the format of a credit card or pen, pricked on a finger and inserted into an off-the-shelf fluorescent reader that provides you with exactly the concentration of the analyte you're looking for," IBM researcher Luc Gervais told Medical Device Daily. "It works like a clinical analyzer, but it has the advantage of being right there next to patients."

The portable diagnostic chip uses capillary forces to analyze tiny samples of serum or blood for the presence of disease markers, typically proteins. Capillary action is the tendency of a liquid to rise in narrow tubes or to be drawn into small openings, much like liquid is absorbed onto a paper towel.

After a sample is pipetted onto the chip, the capillary action - a microfluidics technology - pushes the sample through a set of microscopic chambers where it will react with a disease marker, signaling the amount of protein in the sample.

It works somewhat like a pregnancy test, but produces much more specific results.

"Pregnancy tests require samples of about 100 mL and we use only 5 mL," Gervais said. "The pregnancy tests will only give you an answer if analyte is above or below a certain threshold - yes or no. Our test would provide an answer such as: there is 10 mg/L of C Reactive Protein (CRP is an indicator of inflammation) in the blood, meaning the person is not at risk for heart attack."

The chip measures 1 cm 5 cm, contains sets of micrometer wide channels where the test sample flows through in approximately 15 seconds, faster then traditional tests. That speed can be adjusted to several minutes when the chip requires additional time to read a more complex disease marker. The most critical aspect of the test occurs in the reaction chamber, which is about the diameter of a strand of human hair. The disease marker that is tagged is captured on the surface of the chamber. By shining a focused beam of red light, the tagged marker can be viewed using a portable sensor device that contains a chip similar to those used by digital cameras.

Made of mold-injected plastic, these single-use diagnostics have the potential to lower the cost of testing, reduce turnaround time and reduce overall healthcare tests, according to IBM.

"It's a replacement for clinical analyzers. Instead of taking a large sample and getting results an hour later, you can do it right at the patient's bedside," said Gervais.

"IBM has a medical technology timeline that dates back to the 1950s, so the healthcare industry is not new. But getting into diagnostic testing is new for IBM," Chris Sciacca, manager of IBM communications, told MDD. "We don't intend to start making the tests, but will engage a partner with a license."

That partner is rapid test maker Coris BioConcept (Gembloux, Belgium).

"This microfluidic chip is the next step in the evolution of point of care devices. We look forward to working with the scientists at IBM Research - Zurich to develop this innovation even further," said Thierry Leclipteux, CEO and chief science officer, Coris BioConcept.

An article detailing the work of Gervais and his team is due out in the December issue of Lab on a Chip, a publication of The Royal Society of Chemistry (London).

In the article they detail the integration of microfluidic functional elements and reagents such as detection antibodies (dAbs), capture antibodies (cAbs) and analyte molecules to make the one-step immunoassay. In their initial experiments, the team focuses on CRP, the cardiac marker, and shows how the device uses just 5 mL of human serum to detect CRP at a concentration of 10 ng mL^-1 in less than 3 minutes and below 1 ng mL^-1 within 14 minutes.

Lateral access is offered by more companies"The work presented here may spur the adoption of fluorescence immunoassays using capillary driven microfluidics and polydimethylsiloxane [a type of silicone] substrates for point-of-care diagnostics," they wrote.

Gervais said up to 64 different analytes may be included on the chip. In addition to checking for cardiac markers, the test will be capable of detecting any disease with a biomarker, such as p53 for breast cancer or prostate specific antigen (PSA) for prostate cancer and even influenza virus.

"This chip can diagnose diseases that have established markers not only for cancer and heart disease, but with antibodies generated with viruses and bacteria. It's vast," said Sciacca.

He said the device has already reached proof-of-concept stage and is now ready for testing and commercialization. Manufacturing would be relatively simple since the device has no pumps or electrical devices, relying instead on the power of capillary action.

IBM estimates it could be on the market within two years.

Based on the same technology, Sciacca said IBM will disclose work on tests for neurological diseases such as Parkinson's and Alzheimer's diseases within a few months.

Gervais and his team worked in collaboration with the University Hospital of Basel (Switzerland) to develop the test.