DMD-based LED-illumination Super-resolution and optical sectioning microscopy

TLDR

Super‑resolution three‑dimensional optical microscopy offers unparalleled advantages over electron microscopy and atomic force microscopy for studying biological molecules, pathways, and events in live cells and tissues. The study introduces a novel structured illumination microscopy approach that uses a digital micromirror device for fringe projection and a low‑coherence LED for illumination. This method employs a DMD to project structured fringes while a low‑coherence LED provides illumination. The system achieves 90 nm lateral resolution, 120 μm optical sectioning depth, and a 1.6×10⁷ pixels/s acquisition speed limited by the CCD, while being cost‑effective, speckle‑noise‑free, and easily switchable between 2D super‑resolution and 3D optical sectioning for both fluorescent and non‑fluorescent samples.

Abstract

Super-resolution three-dimensional (3D) optical microscopy has incomparable advantages over other high-resolution microscopic technologies, such as electron microscopy and atomic force microscopy, in the study of biological molecules, pathways and events in live cells and tissues. We present a novel approach of structured illumination microscopy (SIM) by using a digital micromirror device (DMD) for fringe projection and a low-coherence LED light for illumination. The lateral resolution of 90 nm and the optical sectioning depth of 120 μm were achieved. The maximum acquisition speed for 3D imaging in the optical sectioning mode was 1.6×107 pixels/second, which was mainly limited by the sensitivity and speed of the CCD camera. In contrast to other SIM techniques, the DMD-based LED-illumination SIM is cost-effective, ease of multi-wavelength switchable and speckle-noise-free. The 2D super-resolution and 3D optical sectioning modalities can be easily switched and applied to either fluorescent or non-fluorescent specimens.