scholarly journals DMD-based super-resolution structured illumination microscopy visualizes live cell dynamics at high speed and low cost

2019 ◽  
Author(s):  
Alice Sandmeyer ◽  
Mario Lachetta ◽  
Hauke Sandmeyer ◽  
Wolfgang Hübner ◽  
Thomas Huser ◽  
...  

Structured illumination microscopy (SIM) is among the most widely used super-resolution fluorescence microscopy techniques for visualizing the dynamics of cellular organelles, such as mitochondria, the endoplasmic reticulum, or the cytoskeleton. In its most wide-spread implementation, SIM relies on the creation of an interference pattern at the diffraction limit using the coherent addition of laser beams created by a diffraction pattern.Spatial light modulators based on liquid crystal displays allow SIM micro-scopes to run at image rates of up to hundreds of super-resolved images per second. Digital micromirror devices are another natural choice for creating interference-based SIM patterns, but are not used to their fullest potential because of the blazed grating effect. This effect arises due to the fixed angles between which the mirrors can be switched, creating a sawtooth arrangement of mirrors and thus leading to a change in the intensity distribution of the diffracted beams. This results in SIM patterns with varying modulation contrast which are prone to reconstruction artifacts.We have carefully studied the blazed grating effect of DMDs by simulations, varying a range of parameters and compared the simulation results with experiments. This allowed us to identify settings which result in very high modulation contrast across all angles and phases required to generate 2-beam SIM pattern. The use of inexpensive industry-grade CMOS cameras as well as low-cost lasers enabled us to construct a cost-effective, high-speed SIM system. Reconstruction of the super-resolved SIM images is achieved on a recently demonstrated parallel-computing platform, which allowed us to visualize living cells with super-resolution at multiple reconstructed frames per second in real time. We demonstrate the versatility of this new platform by imaging cellular organelle dynamics based on live-cell fluorescent stains as well as with fluorescent protein stained samples.

2021 ◽  
Vol 9 ◽  
Author(s):  
Tianyu Zhao ◽  
Zhaojun Wang ◽  
Tongsheng Chen ◽  
Ming Lei ◽  
Baoli Yao ◽  
...  

Super-resolution microscopy surpasses the diffraction limit to enable the observation of the fine details in sub-cellular structures and their dynamics in diverse biological processes within living cells. Structured illumination microscopy (SIM) uses a relatively low illumination light power compared with other super-resolution microscopies and has great potential to meet the demands of live-cell imaging. However, the imaging acquisition and reconstruction speeds limit its further applications. In this article, recent developments all targeted at improving the overall speed of SIM are reviewed. These comprise both hardware and software improvements, which include a reduction in the number of raw images, GPU acceleration, deep learning and the spatial domain reconstruction. We also discuss the application of these developments in live-cell imaging.


Author(s):  
Mario Lachetta ◽  
Hauke Sandmeyer ◽  
Alice Sandmeyer ◽  
Jan Schulte am Esch ◽  
Thomas Huser ◽  
...  

Digital micromirror devices (DMDs) are spatial light modulators that employ the electro-mechanical movement of miniaturized mirrors to steer and thus modulate the light reflected off a mirror array. Their wide availability, low cost and high speed make them a popular choice both in consumer electronics such as video projectors, and scientific applications such as microscopy. High-end fluorescence microscopy systems typically employ laser light sources, which by their nature provide coherent excitation light. In super-resolution microscopy applications that use light modulation, most notably structured illumination microscopy (SIM), the coherent nature of the excitation light becomes a requirement to achieve optimal interference pattern contrast. The universal combination of DMDs and coherent light sources, especially when working with multiple different wavelengths, is unfortunately not straight forward. The substructure of the tilted micromirror array gives rise to a blazed grating, which has to be understood and which must be taken into account when designing a DMD-based illumination system. Here, we present a set of simulation frameworks that explore the use of DMDs in conjunction with coherent light sources, motivated by their application in SIM, but which are generalizable to other light patterning applications. This framework provides all the tools to explore and compute DMD-based diffraction effects and to simulate possible system alignment configurations computationally, which simplifies the system design process and provides guidance for setting up DMD-based microscopes. This article is part of the Theo Murphy meeting ‘Super-resolution structured illumination microscopy (part 1)’.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Karl Zhanghao ◽  
Xingye Chen ◽  
Wenhui Liu ◽  
Meiqi Li ◽  
Yiqiong Liu ◽  
...  

Abstract Fluorescence polarization microscopy images both the intensity and orientation of fluorescent dipoles and plays a vital role in studying molecular structures and dynamics of bio-complexes. However, current techniques remain difficult to resolve the dipole assemblies on subcellular structures and their dynamics in living cells at super-resolution level. Here we report polarized structured illumination microscopy (pSIM), which achieves super-resolution imaging of dipoles by interpreting the dipoles in spatio-angular hyperspace. We demonstrate the application of pSIM on a series of biological filamentous systems, such as cytoskeleton networks and λ-DNA, and report the dynamics of short actin sliding across a myosin-coated surface. Further, pSIM reveals the side-by-side organization of the actin ring structures in the membrane-associated periodic skeleton of hippocampal neurons and images the dipole dynamics of green fluorescent protein-labeled microtubules in live U2OS cells. pSIM applies directly to a large variety of commercial and home-built SIM systems with various imaging modality.


2019 ◽  
Vol 12 (03) ◽  
pp. 1950014 ◽  
Author(s):  
Xibin Yang ◽  
Qian Zhu ◽  
Zhenglong Sun ◽  
Gang Wen ◽  
Xin Jin ◽  
...  

Structured illumination microscopy (SIM) is a promising super-resolution technique for imaging subcellular structures and dynamics due to its compatibility with most commonly used fluorescent labeling methods. Structured illumination can be obtained by either laser interference or projection of fringe patterns. Here, we proposed a fringe projector composed of a compact multi-wavelength LEDs module and a digital micromirror device (DMD) which can be directly attached to most commercial inverted fluorescent microscopes and update it into a SIM system. The effects of the period and duty cycle of fringe patterns on the modulation depth of the structured light field were studied. With the optimized fringe pattern, [Formula: see text] resolution improvement could be obtained with high-end oil objectives. Multicolor imaging and dynamics of subcellular organelles in live cells were also demonstrated. Our method provides a low-cost solution for SIM setup to expand its wide range of applications to most research labs in the field of life science and medicine.


Nanophotonics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 143-148
Author(s):  
Adrien Descloux ◽  
Marcel Müller ◽  
Vytautas Navikas ◽  
Andreas Markwirth ◽  
Robin van den Eynde ◽  
...  

AbstractSuper-resolution structured illumination microscopy (SR-SIM) can be conducted at video-rate acquisition speeds when combined with high-speed spatial light modulators and sCMOS cameras, rendering it particularly suitable for live-cell imaging. If, however, three-dimensional (3D) information is desired, the sequential acquisition of vertical image stacks employed by current setups significantly slows down the acquisition process. In this work, we present a multiplane approach to SR-SIM that overcomes this slowdown via the simultaneous acquisition of multiple object planes, employing a recently introduced multiplane image splitting prism combined with high-speed SIM illumination. This strategy requires only the introduction of a single optical element and the addition of a second camera to acquire a laterally highly resolved 3D image stack. We demonstrate the performance of multiplane SIM by applying this instrument to imaging the dynamics of mitochondria in living COS-7 cells.


2020 ◽  
Author(s):  
Mario Lachetta ◽  
Hauke Sandmeyer ◽  
Alice Sandmeyer ◽  
Jan Schulte am Esch ◽  
Thomas Huser ◽  
...  

SummaryDigital micromirror devices (DMDs) are spatial light modulators that employ the electro-mechanical movement of miniaturized mirrors to steer and thus modulate the light reflected of a mirror array. Their wide availability, low cost and high speed make them a popular choice both in consumer electronics such as video projectors, and scientific applications such as microscopy.High-end fluorescence microscopy systems typically employ laser light sources, which by their nature provide coherent excitation light. In super-resolution microscopy applications that use light modulation, most notably structured illumination microscopy (SIM), the coherent nature of the excitation light becomes a requirement to achieve optimal interference pattern contrast. The universal combination of DMDs and coherent light sources, especially when working with multiple different wavelengths, is unfortunately not straight forward. The substructure of the tilted micromirror array gives rise to a blazed grating, which has to be understood and which must be taken into account when designing a DMD-based illumination system.Here, we present a set of simulation frameworks that explore the use of DMDs in conjunction with coherent light sources, motivated by their application in SIM, but which are generalizable to other light patterning applications. This framework provides all the tools to explore and compute DMD-based diffraction effects and to simulate possible system alignment configurations computationally, which simplifies the system design process and provides guidance for setting up DMD-based microscopes.


2021 ◽  
Author(s):  
Weisong Zhao ◽  
Shiqun Zhao ◽  
Liuju Li ◽  
Xiaoshuai Huang ◽  
Shijia Xing ◽  
...  

Abstract The spatial resolutions of live-cell super-resolution microscopes are limited by the maximum collected photon flux. Taking advantage of a priori knowledge of the sparsity and continuity of biological structures, we develop a deconvolution algorithm that further extends the resolution of super-resolution microscopes under the same photon budgets by nearly twofold. As a result, sparse structured illumination microscopy (Sparse-SIM) achieves ~60 nm resolution at a 564 Hz frame rate, allowing it to resolve intricate structural intermediates, including small vesicular fusion pores, ring-shaped nuclear pores formed by different nucleoporins, and relative movements between the inner and outer membranes of mitochondria in live cells. Likewise, sparse deconvolution can be used to increase the three-dimensional resolution and contrast of spinning-disc confocal-based SIM (SD-SIM), and operates under conditions with the insufficient signal-to-noise-ratio, all of which allows routine four-color, three-dimensional, ~90 nm resolution live-cell super-resolution imaging. Overall, sparse deconvolution may be a general tool to push the spatiotemporal resolution limits of live-cell fluorescence microscopy.


2018 ◽  
Author(s):  
Jakub Pospíšil ◽  
Tomáš Lukeš ◽  
Justin Bendesky ◽  
Karel Fliegel ◽  
Kathrin Spendier ◽  
...  

AbstractBackgroundStructured illumination microscopy (SIM) is a family of methods in optical fluorescence microscopy that can achieve both optical sectioning and super-resolution effects. SIM is a valuable method for high resolution imaging of fixed cells or tissues labeled with conventional fluorophores, as well as for imaging the dynamics of live cells expressing fluorescent protein constructs. In SIM, one acquires a set of images with shifting illumination patterns. This set of images is subsequently treated with image analysis algorithms to produce an image with reduced out-of-focus light (optical sectioning) and/or with improved resolution (super-resolution).FindingsFive complete and freely available SIM datasets are presented including raw and analyzed data. We report methods for image acquisition and analysis using open source software along with examples of the resulting images when processed with different methods. We processed the data using established optical sectioning SIM and super-resolution SIM methods, and with newer Bayesian restoration approaches which we are developing.ConclusionVarious methods for SIM data acquisition and processing are actively being developed, but complete raw data from SIM experiments is not typically published. Publicly available, high quality raw data with examples of processed results will aid researchers when developing new methods in SIM. Biologists will also find interest in the high-resolution images of animal tissues and cells we acquired. All of the data was processed with SIMToolbox, an open source and freely available software solution for SIM.


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