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Updated: Jun 13, 2026

Simultaneous Multicolor Imaging of Biological Structures with Fluorescence Photoactivation Localization Microscopy
Published on: December 9, 2013
Rapid near-infrared fluorescence excitation-emission matrix spectroscopy for multifluorophore characterization using
Hao Li1, Wei Zheng, Zhiwei Huang
1National University of Singapore, Faculty of Engineering, Department of Bioengineering, Optical Bioimaging Laboratory, 9 Engineering Drive 1, Singapore 117576.
Abstract:
We report on a novel acousto-optic tunable filter (AOTF)-based near-infrared (NIR) fluorescence excitation-emission matrix (EEM) spectroscopy technique for rapid multifluorophore characterization. We implement a unique light filtering module design by using cascaded AOTFs coupled with three orthogonally oriented polarizers to effectively remove the side-ripple artifacts of AOTFs as well as by using a pair of AOTFs coupled with two orthogonally oriented polarizers to improve detection efficiency for high-quality fluorescence EEM acquisitions. NIR fluorescence EEM spectroscopy (41 excitation wavelengths ranging from 550 to 950 nm in 10-nm increments; fluorescence emission from 570 to 1000 nm at 10-nm intervals) can be acquired from fluorescence dyes [e.g., diethylthiatricarbocyanine (DTTC) iodide, oxazine 750, and IR 140] within 10 s or even less, illustrating the potential of the AOTF-based NIR EEM technique developed for rapid multifluorophore analysis and characterization in biochemical and biomedical systems.
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