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Updated: Jul 11, 2026
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LED Thermo Flow — Combining Optogenetics with Flow Cytometry
Published on: December 30, 2016
Practical time-gated luminescence flow cytometry. II: experimental evaluation using UV LED excitation
Dayong Jin1, Russell Connally, James Piper
1Centre for Lasers and Applications, Division of Information and Communication Sciences, Macquarie University, NSW, Australia. jin@ics.mq.edu.au
Summary
A new time-gated luminescence (TGL) flow cytometer using UV LED excitation effectively counts rare Europium-labeled targets. This method achieves high signal-to-background ratios, even in complex samples, demonstrating over 93% counting efficiency.
Area of Science:
- Biomedical Engineering
- Analytical Chemistry
- Optics
Background:
- Time-gated luminescence (TGL) flow cytometry offers potential for rare-event detection.
- Previous work explored UV LED excitation for TGL.
- Autofluorescence and broadband signals pose challenges for conventional methods.
Purpose of the Study:
- To construct and evaluate a practical TGL flow cytometer prototype.
- To utilize UV LED excitation and a gated channel photomultiplier tube (CPMT) for enhanced detection.
- To assess the system's performance in complex sample matrices.
Main Methods:
- A compact TGL flow cytometer was built and optimized for a 6 kHz cycle rate.
- Pulsed UV LED excitation (100 µs) followed by delay-gated detection (60 µs) was employed.
- Europium (Eu3+) luminescence beads were enumerated in autofluorescent water and S101 solutions.
Main Results:
- The TGL flow cytometer successfully distinguished target beads from background noise.
- A maximum signal-to-background ratio of 38:1 was achieved.
- Counting efficiency exceeded 93% compared to conventional methods, with no background contribution from tested matrices.
Conclusions:
- The developed TGL flow cytometer is effective for rare-event detection in challenging samples.
- UV LED excitation combined with gated detection provides high specificity and sensitivity.
- This technology shows promise for applications requiring sensitive and selective cell counting.
