For decades, flow cytometry has been considered a laboratory technology. High-precision optics, sensitive alignment procedures, and demanding operating conditions have confined its use to hospitals, research institutes, and analytical laboratories.
The rqmicro.COUNT platform challenges this limitation.
To demonstrate the robustness of our cartridge-based flow cytometer, we performed mobile water analysis aboard a moving train in Switzerland. During the journey, the instrument continuously measured Total Cell Count (TCC) and Intact Cell Count (ICC) while exposed to constant vibration and movement—conditions that are generally incompatible with conventional flow cytometers.
The experiment demonstrates that portable flow cytometry is no longer a vision for the future. It is already enabling rapid microbiological water analysis wherever samples are collected.
Measuring Water Quality While Travelling
Four water samples were collected during the journey and analyzed directly onboard using rqmicro.COUNT.
Each sample was analyzed for both Total Cell Count (TCC) and Intact Cell Count (ICC).
Sampling locations included:
- Drinking water fountain in Schlieren
- Drinking water fountain at Zurich Main Station
- Tap water from a second-class train restroom
- Tap water from a first-class train restroom
Throughout the journey, the instrument performed the analyses while the train was in motion, demonstrating stable operation under continuous mechanical vibration.
Watch the full experiment in the video below.
Why Conventional Flow Cytometers Stay in the Laboratory
Traditional flow cytometers depend on permanently aligned optical systems. Laser excitation, optical filters, and detectors must remain precisely positioned to ensure reproducible measurements. Even relatively small mechanical disturbances can affect optical alignment, which is why these instruments are typically installed in carefully controlled laboratory environments.
This requirement has historically prevented the widespread use of flow cytometry for field applications and on-site water analysis.
A Different Approach: Cartridge-Based Flow Cytometry
The rqmicro.COUNT platform was designed around a fundamentally different measurement principle.
Instead of using a permanently fixed flow cell, every analysis is performed inside a disposable microfluidic cartridge. Before each measurement, the optical unit automatically aligns itself with the cartridge's analysis channel. This automatic realignment removes the dependence on permanently fixed optics and enables highly reproducible measurements even under challenging operating conditions.
The successful measurements performed aboard a moving train highlight the robustness of this unique system architecture.
Bringing Flow Cytometry to the Point of Sampling
For water hygiene professionals, analytical results are often needed immediately. Waiting for laboratory analysis increases response times and delays decision-making.
Portable flow cytometry enables microbiological testing directly where water samples are collected.
Potential applications include:
- Source water monitoring
- Process water quality control
- Cooling water management
- Distribution system monitoring
- Facility management and water hygiene services
- Environmental water monitoring
- On-site verification after corrective actions
By combining portability with laboratory-grade flow cytometry, rqmicro.COUNT enables faster decision-making and greater operational flexibility for water quality professionals.
A Milestone for Mobile Flow Cytometry
The objective of this demonstration was not simply to operate a flow cytometer on a train.
The moving train represents an environment with continuous vibration, acceleration, and mechanical disturbance. These are conditions under which conventional flow cytometers are generally not designed to operate.
Successfully performing Total Cell Count and Intact Cell Count measurements under these conditions demonstrates the robustness of rqmicro.COUNT and illustrates how cartridge-based flow cytometry extends microbiological water analysis beyond the laboratory.
As demand grows for rapid, on-site microbiological testing, portable flow cytometry opens new opportunities for drinking water monitoring, industrial water management, and environmental analysis.
The future of microbiological water testing is no longer limited to the laboratory. It can travel wherever the sample is collected.
Watch the video linked above to see rqmicro.COUNT performing real-time flow cytometric water analysis aboard a moving train in Switzerland.