Correlative Super‐Resolution Imaging of Cellular Nanopores Facilitated by Transparent Polymer Waveguide Chips

Abstract Super‐resolution optical microscopy (SRM) permits the visualization of subcellular structures of biological samples beyond the diffraction limit of light. To evaluate and utilize the specific strengths of each SRM technique a combined approach in the form of correlative super‐resolution imaging is essential. Here, the correlative SRM imaging of the ultrastructure of rat liver sinusoidal endothelial cells (LSECs) across a large field of view (FOV) with 3D structured illumination microscopy (3D‐SIM) and single‐molecule localization microscopy (SMLM), facilitated by a transparent polymer photonic waveguide chip, is presented. This waveguide is not only used for chip‐based total internal reflection fluorescence (TIRF) excitation across a large FOV, but also enables the excitation and collection of single‐molecule fluorescence via the inverted microscope configuration. Furthermore, the structural design of the waveguides allows to identify and correlate sample positions across multiple microscopes. This correlative SIM and multi‐modality SMLM imaging provides a high throughput (FOV of ≈180 µm × 120 µm) method to analyze the structural morphology of LSECs with high spatial resolution (≈50 nm). Furthermore, waveguide chip‐based TIRF excitation also yields a significant reduction of background signals.