Structured illumination multimodal 3D-resolved quantitative phase and fluorescence sub-diffraction microscopy

摘要

Sub-diffraction resolution imaging has played a pivotal role in biologicalresearch by visualizing key, but previously unresolvable, sub-cellularstructures. Unfortunately, applications of far-field sub-diffraction resolutionare currently divided between fluorescent and coherent-diffraction regimes, anda multimodal sub-diffraction technique that bridges this gap has not yet beendemonstrated. Here we report that structured illumination (SI) allowsmultimodal sub-diffraction imaging of both coherent quantitative-phase (QP) andfluorescence. Due to the conventional fluorescent applications of SI, we firstdemonstrated the principle of SI-enabled three-dimensional (3D) QPsub-diffraction imaging with calibration microspheres. Image analysis confirmedenhanced lateral and axial resolutions over diffraction-limited QP imaging, andestablished striking parallels between coherent SI and conventional opticaldiffraction tomography. We next introduce an optical system utilizing SI toachieve 3D sub-diffraction, multimodal QP/fluorescent visualization of A549biological cells fluorescently tagged for F-actin. Our results suggest that SIhas unique utility in studying biological phenomena with significant molecular,biophysical, and biochemical components.