Testing lab samples of blood is one thing; there’s lots of control achieved by isolating components of the blood before testing. Testing whole blood, unfiltered and with all components in their usual mix, is another thing. The thing is; testing whole blood is what’s required in the real world. Whole blood is complicated by the presence of ions (charged particles) and proteins, which can confuse detection devices. Researchers at Yale University have got around the problem by developing minute sensors made of nanowire.

Current blood testing involves taking the sample, sending it to the lab where a centrifuge separates the different components, then isolating the plasma and putting it through an hours-long chemical analysis. The process is lengthy and labor intensive. By using nanosensors in the blood and a detection device equipped with a customized chip, blood can be screened for specific type of markers.

To overcome the challenge of whole blood detection, the researchers developed a novel device that acts as a filter, catching the biomarkers—in this case, antigens specific to prostate and breast cancer—on a chip while washing away the rest of the blood. Creating a buildup of the antigens on the chip allows for detection down to extremely small concentrations, on the order of picograms per milliliter, with 10 percent accuracy. This is the equivalent of being able to detect the concentration of a single grain of salt dissolved in a large swimming pool.

Until now, detection methods have only been able to determine whether or not a certain biomarker is present in the blood at sufficiently high concentrations for the detection equipment to give reliable estimates of its presence. “This new method is much more precise in reading out concentrations, and is much less dependent on the individual operator’s interpretation.”

[Source: EurekAlert]

Many research groups are working on the ‘lab on a chip’ concept. This research is the first one to demonstrate working with whole blood. From here the concept needs to be verified (replicated by others) and ramped up for application. Potentially, the technology can be used for in-the-field testing of blood – as in a doctor’s office – saving both time and labor.