麻豆淫院

Structured illumination microscopy (SIM) is the most preferable system for live-cell super-resolution imaging. It enables the observation of intricate subcellular dynamics. However, conventional SIM has long relied on the complex rotation of one-dimensional stripe illumination at three angles, requiring nine exposures to reconstruct a uniform super-resolution image. This greatly hinders imaging speed and causes unnecessary photobleaching, limiting the available information flux in live-cell imaging.

Professor Xi Peng's team from the College of Future Technology at Peking University has developed a triangle-beam interference SIM (3I-SIM) that enables gentler, sustained super-resolution live-cell imaging. This novel method upgrades the super-resolution imaging to an unprecedented kilo-Hz speed and half-day-long duration, enabling the study of complex and rapid biological processes with higher data throughput.

The work is in Nature Photonics.

Drawing inspiration from the simplicity and efficiency of triangular structures, this study employs triangular-beam interference to achieve 2D lattice modulation, expanding high-frequency spatial information in both dimensions in a single exposure. While conventional 2D-SIM requires multiple 1D modulation at different angles, the 3I-SIM generates a 2D hexagonal lattice illumination with 3-beam interference.

With only seven raw frames shifting in 1D required, 3I-SIM effectively mitigates photobleaching during acquisition and improves speed by 3-fold through minimizing redundant spatial sampling and continuous rolling reconstruction. As a result, 3I-SIM achieves an imaging speed of up to 1,697 Hz under single-frame rolling reconstruction, and enables up to 13-hour-long super-resolution imaging with more than 100,000 recording time points.

The breakthrough of 3I-SIM has enabled the study of organelle activities that are unreachable with previous techniques. Using 3I-SIM, the research team recorded fine morphological changes in neuronal growth cones for up to 13 hours, as well as the transient signals from actin structures regulating endoplasmic reticulum dynamics.

The 3I-SIM system can be flexibly upgraded on common 2D-SIM platforms, effectively lowering the technical barrier and enabling more research teams to access next-generation live-cell super-resolution imaging.