Researchers in Germany want to shrink flow cytometers—currently as large as home washing machines—down to the size of a shoebox, while making their device more accurate
Flow cytometers, essential to the diagnosis of blood cancers, are in for a major makeover, if researchers at a technology institute in Germany are successful at engineering a smaller, cheaper, and more automated version of today’s large and expensive flow cytometer systems. If this happens, it would make it possible for clinical laboratories in many community hospitals to use these more compact flow cytometers in support of patient care.
Flow cytometers have been around for about 40 years; however, the equipment is expensive, large, and the process so lengthy and complex that only specially-trained scientists can operate it. Those factors make it difficult for patients and clinicians to reap the full benefit of the information that flow cytometry can yield.
Designing a Flow Cytometer That is Smaller, Faster, Cheaper
That may be changing thanks to the development of a much smaller, more automated flow cytometer. The PoCyton is a product being developed by the Fraunhofer Institute for Chemical Technology (ICT-IMM) in Pfinztal, Germany.
Traditional cytometers are approximately the size of two washing machines, but the PoCyton is about the size of a shoebox. It also enables “tests to be carried out around twenty times faster,” according to Michael Bassler, PhD, a research scientist working at ICT-IMM.
In addition to being smaller and faster, the PoCyton is much less costly compared to other types of cytometers. A lower price would make it easier for more medical laboratories to acquire these systems. In turn, that would improve local access to flow cytometry services for both clinicians and patients.
How PoCyton Flow Cytometry Works
When flow cytometry is performed, a fluorescent dye that attaches only to cancerous cells is injected into a blood sample. Traditional flow cytometers require daily recalibration. Typically, the operator must manually add the dye to the blood sample. With the PoCyton, the dye is added automatically.
The key to the process is a very narrow passage that allows the device to count the cells one at a time, so that none can “hide” behind others. The fact that the cells are counted one at a time means fewer errors, according to Bassler. “A mere 10 mL sample of blood contains around one billion suspended objects,” he says. “Of these, only five are circulating tumor cells, even in a very sick patient.”
Emerging Technologies Related to Cytometry
The PoCyton is just one of several new technologies related to cytometry under development. Many others are being tested around the world:
• At the University of California, Berkeley, scientists are working on “an integrated microfluidic chip which can adapt to sort cancer and other types of cells based on their cell surface protein expression,” which the scientists are calling NanoCytometry.
• The Amnis ImageStreamX Mark II “combines the speed, statistical power, and fluorescence sensitivity of flow cytometry with the functional insights of high resolution microscopy.”
• At Stanford University, researchers are working to combine flow cytometry and mass spectrometry, which would “greatly increase the number of parameters that are measurable with single-cell resolution.”
• The Flow Cytometry Core (FCC) Facility at the University of Rochester Medical Center is using a device called the CyTOF Mass Cytometer to “measure over 30 simultaneous parameters allowing for complex immunophenotyping of cells as well as examining multiple internal cell targets without the limitations traditional fluorescence flow cytometry has.”
Improved Technology Produces Diverse Applications
As the technology improves, applications for using it outside of the clinical laboratory increase. For example, flow cytometry can be used to ensure a municipality’s water supply remains safe to drink.
The Fraunhofer researchers are collaborating with rqmicro, a Swiss rapid quantitative microbiology company, to use flow cytometry technology to count bacteria such as E. coli and Enterococci in drinking water.
Traditional bacterial testing of water involves placing samples in petri dishes and waiting for the bacteria to multiply enough to be counted. The process can take up to 10 days to return results. By contrast, the PoCyton flow cytometer can return similar results in less than a tenth the time. “Our flow cytometer can perform the same analysis within an hour,” stated Bassler. This means an onsite inspector could perform the tests remotely in situ and inform the inhabitants before departing. This would be a boon to many regions of the world where potable water is in short supply.
Finding Uses for Flow Cytometry Outside Medical Laboratories
Often, medical laboratory professionals overlook the fact that the same diagnostic technologies they use in their clinical labs to support clinical care can make valuable contributions for non-medical purposes. The example of using the PoCyton flow cytometer in support of bacterial testing for municipal water systems aptly illustrates one such opportunity.
Researchers at the Fraunhofer Institute for Chemical Technology did not provide an estimate of when their smaller flow cytometry system would be ready for clinical trials.