Counting Chips
A new microfluidic device the size of a credit card may offer rapid, inexpensive blood cell counts that require only tiny samples
Overworked laboratories may soon have a new tool for tackling slow turnaround times. One of the most commonly used – and yet most resource-intensive – tests in clinical laboratories is the complete blood count (CBC). The routine test requires the use of a hematology analyzer to count the cells in a blood sample – but the machines are expensive, take up space in crowded labs, and require trained technicians to operate. With all these restrictions, patients must travel to hospitals or centralized laboratories to have these simple tests done. “It slows turnaround time, limits throughput in hospitals, and limits accessibility in resource-limited settings,” says Umer Hassan, lead author of a paper that proposes a new type of CBC device.
a. Schematic of the biosensor, with inset showing the microfabricated coplanar electrodes aligned with the cell counting aperture. b. Representative voltage pulses generated as the individual cells pass over the electrodes. c. Pulse amplitude histogram showing distinct white blood cell populations.
Image Credit: TECHNOLOGY.
Hassan’s solution? An automated chip the size of a credit card that electrically detects the size and membrane properties of cells in a blood sample (1). The microfluidic device can use samples as small as a single microliter to count platelets and erythrocytes, or up to 11 µL for leukocyte counts and differentials. And it’s not just the small sample size that makes the chip an intriguing new piece of technology – there’s a significant time saving too. “Currently, in hospital settings, blood samples are transported to a testing laboratory and it takes a few hours to a day to get the results back to the patient,” says Hassan. “Our technology can provide the cell count results in less than 30 minutes at the point of care, and completely eliminates sample transportation.” The chips themselves are intended to be disposable, reducing the cost of a CBC to less than US$10.
One of the most compelling possible uses for the technology is in resource-limited settings where laboratory tests are often inaccessible due to cost, poor laboratory facilities, or the difficulty of follow-up after days spent waiting for results. The device’s ease-of-use and the ability to interface with smartphones and tablets enable a point-of-care device that can rapidly transmit results to a provider anywhere in the world. This means that there’s no need for a highly trained professional at the point of care – reducing costs and allowing the device to be used in all kinds of settings. For instance, a portable device carried on an ambulance could provide results that might shape the care a patient receives en route to the hospital or provide emergency departments with CBC results upon arrival. Certainly, once the prototype is complete and on-site clinical studies have been conducted, the chip holds the potential to improve the throughput of hospital laboratories and the speed at which patients receive care. MS
- U Hassan et al., “A microfluidic biochip for complete blood cell counts at the point-of-care”, Technology, 3, 201–213 (2015).
While obtaining degrees in biology from the University of Alberta and biochemistry from Penn State College of Medicine, I worked as a freelance science and medical writer. I was able to hone my skills in research, presentation and scientific writing by assembling grants and journal articles, speaking at international conferences, and consulting on topics ranging from medical education to comic book science. As much as I’ve enjoyed designing new bacteria and plausible superheroes, though, I’m more pleased than ever to be at Texere, using my writing and editing skills to create great content for a professional audience.
