A User-Friendly Two-color Super-resolution Localization Microscope

Opt Express. 2015. 23(2):1879-87.

Teng Zhao,1 Ying Wang,1 Yuanliang Zhai,2 Xiaoxuan Qu,2 Aifang Cheng,2 Shengwang Du,1 and M. M. T. Loy1,*

1Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China

2Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China

Abstract

We report a robust two-color method for super-resolution localization microscopy. Two-dye combination of Alexa647 and Alexa750 in an imaging buffer containing COT and using TCEP as switching regent provides matched and balanced switching characteristics for both dyes, allowing simultaneous capture of both on a single camera. Active sample locking stabilizes sample with 1nm accuracy during imaging. With over 4,000 photons emitted from both dyes, two-color superresolution images with high-quality were obtained in a wide range of samples including cell cultures, tissue sections and yeast cells.

ATM protein is located on presynaptic vesicles and its deficit leads to failures in synaptic plasticity

J Neurophysiol., 2016, 13:jn.00006.2016. doi

Graham Vail13, Aifang Cheng2, Yu Ray Han1, Teng Zhao3, Shengwang Du3, Michael M.T. Loy3, Karl Herrup2, Mark R. Plummer1, 4

1Dept. of Cell Biology and Neuroscience, Rutgers University

2Division of Life Science and the State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology

3Dept. of Physics, Hong Kong University of Science and Technology

4Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey

Abstract

Ataxia-telangiectasia is a multi-systemic disorder that includes a devastating neurodegeneration phenotype. The ATM (ataxia-telangiectasia mutated) protein is well-known for its role in the DNA damage response. Yet ATM is also found in association with cytoplasmic vesicular structures - endosomes and lysosomes as well as neuronal synaptic vesicles. In keeping with this latter association, electrical stimulation of the Schaffer collateral pathway in hippocampal slices from ATM-deficient mice does not elicit normal long term potentiation (LTP). The current study was undertaken to assess the nature of this deficit. Theta burst-induced LTP was reduced in Atm-/- animals with the reduction most pronounced at burst stimuli that included six or greater trains. To assess whether the deficit was associated with a pre- or post-synaptic failure, we analyzed paired-pulse facilitation and found that it too was significantly reduced in Atm-/- mice. This indicates a deficit in presynaptic function. As further evidence that these synaptic effects of ATM deficiency were presynaptic, we used stochastic optical reconstruction microscopy (STORM). Three-dimensional reconstruction revealed that ATM is significantly more closely associated with Piccolo (a pre-synaptic marker) than with Homer1 (a post-synaptic marker). These results underline how, in addition to its nuclear functions, ATM plays an important functional role in the neuronal synapse where it participates in the regulation of presynaptic vesicle physiology.

A Mitochondrion-Specific Photoactivatable Fluorescence Turn-On AIE-Based Bioprobe for Localization Super-Resolution Microscope

Adv. Mater., 2016, 28(25): 5064-71.

Xinggui Gu1,2, Engui Zhao1,2, Teng Zhao2, Miaomiao Kang2,3, Chen Gui1,2, Jacky W. Y. Lam1,2, Shengwang Du2, Michael M. T. Loy2 and Ben Zhong Tang1,2,4,*

1HKUST-Shenzhen Research Institute, Shenzhen, China

2Departments of Chemistry and Physics, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Hong Kong, China

3Department of Neurobiology and Anatomy Zhongshan School of Medicine Sun Yat-sen University Guangzhou , China

4Guangdong Innovative Research Team SCUT-HKUST Joint Research Laboratory State Key Laboratory of Luminescent Materials and Device South China University of Technology Guangzhou 51640 , China

Abstract

A novel mitochondrion-specific photo-activatable fluorescence turn-on bioprobe, named as o-TPE-ON+, is designed and readily prepared, operating through a new photoactivatable mechanism of photocyclodehydrogenation. This bioprobe exhibits unique photoactivation behavior in cells, and is applied to super-resolution imaging of mitochondrion and its dynamic investigation in both fixed and live cells under physiological conditions without any external additives.

Faster super-resolution imaging of high density molecules via a cascading algorithm based on compressed sensing

Optics Express Vol. 23, Issue 14, pp. 18563-18576 (2015)

Yajuan Du,1,2 Hao Zhang,3 Mengying Zhao,2 Deqing Zou,1 and Chun Jason Xue2,*

1Service Computing Technology and System Laboratory of Ministry of Education, Cluster and Grid Computing Laboratory, School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan, China

2Department of Computer Science, City University of Hong Kong, Hong Kong, China

3Nanobioimaging Limited, Science Park, Hong Kong, China

Abstract

This paper proposes a cascading algorithm (CSR) based on compressed sensing, which aims to reduce intensive computations in super-resolution imaging of fluorescence microscopy. Performance of existing algorithms such as CVX and L1H drop sharply when applied to obtain finer images with high density molecules. CSR fully exploits the extreme sparsity property of molecules in the compressed sensing model and progressively restricts solution space stage by stage. We perform a comprehensive study of existing algorithms and the proposed algorithm under different resolutions and molecules' densities. Simulation and experimental results confirm the performance advantage of CSR when applied to recover dense molecules.