Hong Kong University of Science and Technology View Institution's Website 10 articles published in JoVE Developmental Biology Visualizing Low-Abundance Proteins and Post-Translational Modifications in Living Drosophila Embryos via Fluorescent Antibody Injection Qihong Zheng*1, Xiaoxiang Xiang*1, Yan Yan2,3, Huapeng H. Yu1 1School of Life Sciences, SUSTech University, 2Shenzhen PKU-HKUST Medical Center, 3Division of Life Science, Hong Kong University of Science and Technology This protocol describes the customized antibody-based fluorescence labeling and injection into early Drosophila embryos to enable live imaging of low-abundance proteins or post-translational modifications that are challenging to detect using traditional GFP/mCherry-tag approaches. Bioengineering Optical Trapping of Plasmonic Nanoparticles for In Situ Surface-Enhanced Raman Spectroscopy Characterizations Xin Dai1,2, Wenting Qiu1,2, Jinqing Huang1,2 1HKUST-Shenzhen Research Institute, 2Department of Chemistry, The Hong Kong University of Science and Technology The present protocol describes a convenient approach to integrating optical trapping and surface-enhanced Raman spectroscopy (SERS) to manipulate plasmonic nanoparticles for sensitive molecular detection. Without aggregating agents, the trapping laser assembles plasmonic nanoparticles to enhance the SERS signals of target analytes for in situ spectroscopic measurements. Bioengineering High-Speed Ultraviolet Photoacoustic Microscopy for Histological Imaging with Virtual-Staining assisted by Deep Learning Xiufeng Li1, Lei Kang1, Claudia T. K. Lo1, Victor T. C. Tsang1, Terence T. W. Wong1 1Translational and Advanced Bioimaging Laboratory, Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology A high-speed and open-top ultraviolet photoacoustic microscope that can provide histological images intraoperatively for surgical margin analysis is demonstrated, including the system configuration, optical alignment, sample preparation, and experimental procedures. Bioengineering In vivo Imaging of Biological Tissues with Combined Two-Photon Fluorescence and Stimulated Raman Scattering Microscopy Wanjie Wu1, Xuesong Li1, Jianan Y. Qu1,2,3,4, Sicong He5 1Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, 2State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, 3Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, 4Molecular Neuroscience Center, The Hong Kong University of Science and Technology, 5Department of Biology, School of Life Sciences, Southern University of Science and Technology Stimulated Raman scattering (SRS) microscopy allows label-free imaging of biomolecules based on their intrinsic vibration of specific chemical bonds. In this protocol, the instrumental setup of an integrated SRS and two-photon fluorescence microscope is described to visualize cellular structures in the spinal cord of live mice. Bioengineering Molecular Spring Constant Analysis by Biomembrane Force Probe Spectroscopy Peyman Obeidy1, Haoqing Wang1,2,3, Mingqin Du1, Huiqian Hu1,4, Fang Zhou1, Haoruo Zhou5, Hao Huang5, Yunduo Charles Zhao1,2, Lining Arnold Ju1,2,3 1School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, 2Charles Perkins Centre, The University of Sydney, 3Heart Research Institute, 4Department of Chemistry, The Hong Kong University of Science and Technology, 5School of Aerospace, Mechanical and Mechatronic Engineering, Faculty of Engineering, The University of Sydney A biomembrane force probe (BFP) is an in situ dynamic force spectroscopy (DFS) technique. BFP can be used to measure the spring constant of molecular interactions on living cells. This protocol presents spring constant analysis for molecular bonds detected by BFP. Chemistry Fabrication of Thin Film Silver/Silver Chloride Electrodes with Finely Controlled Single Layer Silver Chloride Kai Chun Eddie Tjon1, Jie Yuan1 1Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology This paper aims to present a method to form smooth and well-controlled films of silver chloride (AgCl) with designated coverage on top of thin film silver electrodes. Biology A Labor-saving and Repeatable Touch-force Signaling Mutant Screen Protocol for the Study of Thigmomorphogenesis of a Model Plant Arabidopsis thaliana Kai Wang1, Kayin Law1, Manhin Leung1, Waishing Wong1, Ning Li1,2 1Division of Life Science, Energy Institute, Institute for the Environment, The Hong Kong University of Science and Technology, 2Shenzhen Research Institute, The Hong Kong University of Science and Technology A gentle touch-force loading machine is built from human hair brushes, robotic arms and a controller. The hair brushes are driven by robotic arms installed on the machine and move periodically to apply touch-force on plants. The strength of machine-driven hair touches is comparable to that of manually applied touches. Biochemistry Fluorescent Silver Staining of Proteins in Polyacrylamide Gels Alex Y. H. Wong1, Sheng Xie1, Ben Zhong Tang2, Sijie Chen1 1Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, 2Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute of Molecular Functional Materials, State Key Laboratory of Neuroscience, Division of Biomedical Engineering, and Division of Life Science, Hong Kong University of Science and Technology Here, we describe a detailed protocol outlining a new fluorescent staining technique for total protein detection in polyacrylamide gels. The protocol utilizes a silver ion-specific fluorescence turn-on probe, which detects Ag+-protein complexes, and eliminates certain limitations of traditional chromogenic silver stains. Immunology and Infection Photobleaching Enables Super-resolution Imaging of the FtsZ Ring in the Cyanobacterium Prochlorococcus Yuanchao Zhan1, Yaxin Liu1, Qinglu Zeng1,2,3 1Department of Ocean Science, Hong Kong University of Science and Technology, 2Division of Life Science, Hong Kong University of Science and Technology, 3HKUST Shenzhen Research Institute Here we describe a photobleaching method to reduce the autofluorescence of cyanobacteria. After photobleaching, stochastic optical reconstruction microscopy is used to obtain three-dimensional super-resolution images of the cyanobacterial FtsZ ring. Bioengineering Microfluidic Mixers for Studying Protein Folding Steven A. Waldauer1, Ling Wu1, Shuhuai Yao2, Olgica Bakajin3, Lisa J. Lapidus1 1Department of Physics and Astronomy, Michigan State University, 2Department of Mechanical Engineering, Hong Kong University of Science and Technology, 3Center for Biophotonics, University of California, Davis In this work we explain the fabrication and use of a microfluidic mixer capable of mixing two solutions in ~8 μs. We also demonstrate the use of these mixers with spectroscopic detection using UV fluorescence and fluorescence resonance energy transfer (FRET).