One of the most commonly ordered blood tests is the complete blood cell count. Currently, the gold standard for the test requires the use of a lab with bulky and expensive equipment. But now, a new biosensor based on a microfluidic biochip promises to cut the need for a lab and bring the test to the patient’s bedside.
The innovation could make the diagnosis and screening of hundreds of diseases and treatments faster, easier and cheaper, suggest researchers from the University of Illinois at Urbana-Champaign (UIUC), who describe their new biosensor in the journal Technology.
Principal investigator Rashid Bashir, a professor of engineering at UIUC, says the biosensor could improve patient care in a number of settings, and adds:
“One of the [most] compelling is in resource-limited settings, where laboratory tests are often inaccessible due to cost, poor prevalence of laboratory facilities and the difficulty of follow-up upon receiving results that take days to process.”
The team believes the new technology can be developed into a portable blood cell counter that gives results in minutes from a single drop of blood, without the need for trained professionals to operate it.
The complete blood cell count – also known as the full blood count or the full blood exam – is one of the tests most frequently requested by doctors and other medical professionals. The results typically include measures of white blood cells, red blood cells, platelets and hemoglobin.
To obtain the best results, the complete blood cell count is currently performed by trained technicians in a lab using heavy, costly equipment called hematology analyzers. The patient either has to attend a facility with a lab, or their drawn blood sample has to be specially transported to the lab.
Such constraints make complete blood count tests difficult to access in settings where medical resources are scarce. They also slow down turnaround time and limit throughput in hospitals, note the authors.
In their paper, the researchers describe how their biosensor yields counts of red blood cells, platelets and white blood cells (with its three-part differential) from only 11 microliters of blood.
The white blood cell count – with differentials – is used to assess the body’s ability to fight infection. It includes a count of white blood cells, plus a breakdown of the relative proportions of different types of white blood cells.
The biosensor electrically counts the different types of blood cells based on their size and membrane properties.
For the white blood cell and differential count, the device used 10 microliters of blood. It picks out and destroys red blood cells and individually counts the remaining white blood cells. Then, specific types of white blood cells – for example, neutrophils – are counted using multi-frequency analysis, which is sensitive to different membrane properties.
For the red blood cell and platelet count, the biosensor uses 1 microliter of whole blood. After the sample is diluted with saline on the chip, the cells are counted electrically.
The total time to obtain the results is under 20 minutes, the authors note.
First author Dr. Umer Hassan, a researcher in bioelectronics, says there is huge potential for commercializing the technology and concludes:
“The translation of our technology will result in minimal to no experience requirement for device operation. Even, patients can perform the test at the comfort of their home and share the results with their primary care physicians via electronic means too.”
The team is already developing a portable prototype of the cell counter. The base unit of the reader will likely be hand-held and will take cartridges about the size of a credit card. Dr. Hassan says they estimate the cost of a test will be around $10 instead of the $100 that a current test costs.
Prof. Bashir says the technology is scalable and they also plan to investigate using it in other areas, such as animal diagnostics, blood transfusion analysis and blood cell counting for managing chemotherapy treatments.
Meanwhile, Medical News Today recently learned about new chip-based technology that uses an oscillating electrical field to quickly and easily isolate nanoparticles from blood. Writing in the journal Small, engineers from the University of California-San Diego describe how their innovation could be used to remove drug-carrying nanoparticles from blood.