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Updated: Jul 12, 2026
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Effective Detection of Hoechst Side Population Cells by Flow Cytometry
Published on: August 23, 2024
Evaluation of a green laser pointer for flow cytometry
Robert C Habbersett1, Mark A Naivar, Travis A Woods
1The National Flow Cytometry Resource, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Summary
Low-cost DPSS laser pointers can be used in flow cytometry, offering a cheaper alternative to expensive lasers. These lasers provide stable performance for analyzing microspheres and detecting low levels of fluorescent molecules.
Area of Science:
- Biotechnology
- Analytical Chemistry
- Optical Engineering
Background:
- Conventional flow cytometers utilize costly, high-power lasers, increasing system expenses and energy demands.
- Red diode lasers offer cost and power benefits but restrict fluorophore choices.
- Diode-pumped solid-state (DPSS) laser modules present wavelength flexibility but have been limited by concerns over emission stability.
Purpose of the Study:
- To evaluate the feasibility of using low-cost DPSS laser pointer modules as excitation sources in flow cytometry.
- To assess the noise characteristics and performance of a DPSS 532 nm laser pointer module in a custom-built flow cytometer.
Main Methods:
- Evaluated noise characteristics of a $160 DPSS 532 nm laser pointer module.
- Integrated the laser module into a custom flow cytometer for microsphere analysis.
- Measured fluorescence from calibration and alignment microspheres using varying laser power and transit times.
Main Results:
- Eight out of ten DPSS laser modules exhibited low noise (<0.6% RMS noise).
- Flow cytometry analysis of microspheres yielded coefficient of variation (CV) of ~3.3% with the laser pointer.
- Achieved a detection limit of <20 phycoerythrin molecules per particle with extended transit times and low laser power (<1 mW).
- Reduced transit time (25 µs) and increased laser power (2.4 mW) resulted in a detection limit of ~75 phycoerythrin molecules and CVs of ~2.7%.
Conclusions:
- Low-cost DPSS laser pointer modules demonstrate quiet operation and suitability for flow cytometry applications.
- The performance, cost, size, and power efficiency suggest DPSS lasers are viable alternatives, especially in systems supporting extended transit times.
