Dual-mode imaging flow cytometer for simultaneous scattering and fluorescence imaging of phytoplankton.

We propose what we believe to be a novel LED-based light-sheet microscopy-in-flow system that integrates scattering and chlorophyll fluorescence imaging for phytoplankton analysis. Compared to conventional laser light sources, LED light sources exhibit significantly lower coherence, effectively reducing speckle noise. This enhancement improves the quality of scattering imaging and helps preserve the fine structural details of phytoplankton cells. The fluorescence images facilitate phytoplankton detection and reveal the intracellular distribution of chlorophyll/chloroplasts, while the scattering images provide complementary morphological information, particularly for non-fluorescent cell structures. This dual-modality imaging approach enables a more comprehensive characterization of phytoplankton and other particles in natural water samples. Experimental results demonstrate that the system can simultaneously capture both chlorophyll fluorescence and scattering images of flowing phytoplankton cells. With its ability to provide enhanced imaging quality and structural insights, this LED-based light-sheet microscopy-in-flow system has strong potential for automated and accurate phytoplankton water sample analysis, contributing to advancements in aquatic environment monitoring and oceanographic research.