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🔬HBmito Crimson — a membrane-anchored voltage sensor that captures mitochondrial near-field potential (Vnf) in living cells at 1000 fps.⚡ Discovered miniature "flickers" — 1000× smaller than action potentials 📄 doi.org/rf2d #Mitochondria #SuperResolution #VoltageImaging #Bioimaging #PhotoniX

Imaging mitochondrial electric flickers in intact cells with a membrane-anchored indicator - PhotoniX

Mitochondria are excitable organelles, and their electrophysiological activity across the inner mitochondrial membrane (IMM) plays a critical role in energy metabolism, cell signaling and cell fate regulation. While the transmembrane voltage of the IMM (Δψm) is traditionally measured with Nernstian dyes such as tetramethylrhodamine methyl ester (TMRM), here we introduce HBmito Crimson (HBmito), a novel membrane-anchored voltage sensor to probe mitochondrial near-field potential (Vnf) in intact cells by capturing fluorescence signal variations through rapid optical imaging. Vnf encompasses surface potential and the innermost portion of Δψm. During mitochondrial action potential, HBmito-reported Vnf-related signals show up to a 1.9-fold increase, concurrent with Δψm changes reported by TMRM. At an imaging rate of 1000 frames per second, transient miniature Vnf-related flickers were further revealed. And these events were three orders of magnitude smaller than action potentials and likely reflected the activity of individual mitochondrial ionic channels. These results provide the first optical imaging evidence of fundamental electrophysiological events in intact mitochondria, and highlight a novel approach for studying excitable membranes.

doi.org

Introducing #FASIM: A new microscopy method combining SIM with fluorescence anisotropy, ~100 nm resolution with 0.56% relative error—a >20-fold accuracy improvement, allowing us to map the "crowdedness" (viscosity/molecular interactions) in in live cell in real-time. doi.org/10.64898/202...

Fluorescence anisotropy structured illumination microscopy for quantitative super-resolved mapping of cell microenvironment and cytoskeletal dynamics

The crowded intracellular milieu shapes organelle architecture and dynamics, yet nanoscale heterogeneity in its physicochemical properties remains difficult to visualize with conventional fluorescence anisotropy (FA) imaging. Here, we develop fluorescence anisotropy structured illumination microscopy (FA-SIM), which employs orthogonal-polarization structured illumination with dual-angle detection to achieve ∼100-nm resolution and quantitative FA retrieval with 0.56% relative error, representing over 20-fold higher accuracy than conventional FA imaging. With low phototoxicity, FA-SIM enables dual-color, hour-long quantitative super-resolution imaging in cells. Using viscosity standards, defined nanoparticles and small-molecule drug binding assays, we validate FA-SIM as a quantitative reporter of rotational mobility and molecular interactions. In cells, FA-SIM resolves nanoscale crowding heterogeneity, correlates anisotropy landscapes with condensate dynamics, and uncovers a radial crowding gradient across the microtubule network and mitotic spindle. Long-term dual-color imaging further resolves coordinated actin–microtubule remodeling and associated microenvironmental changes. By enabling quantitative, super-resolved mapping of intracellular physical properties in living systems, FA-SIM provides a powerful platform for investigating the physical regulation of cellular organization and dynamics in health and disease. ### Competing Interest Statement Dr. Peng Xi holds the position of Chief Technology Officer (CTO) at Airy Technologies. He declares that there are no additional financial or personal interests that could be perceived as a conflict of interest in relation to the research presented in this paper. The other authors declare no competing interests. National Natural Science Foundation of China, 62025501, 31971376, 92150301, 62411540238, 62335008, 62405010 National Key R&D Program of China, 2022YFC3401100

doi.org

Triangle-Beam Interference SIM (3I-SIM)—a method replaces rotating stripes with hexagonal lattice. This innovation slashes redundancy and unlocks breathtaking speed. The system achieves imaging at up to 1,697 Hz, 13 hours, 100,000 snapshots in action: www.sciencenewstoday.org/the-secret-w...

The Secret World of Living Cells Comes Alive With a New Microscope

For as long as humans have peered through lenses, the microscope has been our gateway to hidden worlds. From Robert…

sciencenewstoday.org

Nat. Photonics🔬 Meet 3I-SIM! Instead of stripes, we use 3-beam to generate 2D hex pattern for simultaneous 2D SIM modulation, with >100,000 frames, 13 h neuronal cell movies, ER–lipid-droplet kiss-n-run and millisecond tango. All hard&software open. doi.org/10.1038/s415... @pku1898.bsky.social

Triangle-beam interference structured illumination microscopy - Nature Photonics

Triangle-beam interference structured illumination microscopy leverages radially polarized beams to generate two-dimensional lattice illumination patterns. The technique enables a temporal resolution ...

doi.org

C²SD-ISM combines physical defocus rejection (spinning disk) with adaptive algorithm (DPA-PR), breaking depth limits in tissue super-resolution (↑180 μm), enhances fidelity (92% linear correlation), and supports high-throughput imaging. doi.org/10.1038/s413... Github: github.com/Chauncey-Leu....

High-fidelity tissue super-resolution imaging achieved with confocal2 spinning-disk image scanning microscopy - Light: Science & Applications

C²SD-ISM integrates an SD and a DMD to form a dual confocal configuration, enabling deep-tissue super-resolution imaging with DPA-PR reconstruction.

doi.org