Lehigh University

9 articles published in JoVE

• Bioengineering

  
  Size Exclusion Chromatography to Analyze Bacterial Outer Membrane Vesicle Heterogeneity Shannon M. Collins¹, Justin B. Nice¹, En Hyung Chang¹, Angela C. Brown^{1 1}Department of Chemical and Biomolecular Engineering, Lehigh University Bacterial vesicles play important roles in pathogenesis and have promising biotechnological applications. The heterogeneity of vesicles complicates analysis and use; therefore, a simple, reproducible method to separate varying sizes of vesicles is necessary. Here, we demonstrate the use of size exclusion chromatography to separate heterogeneous vesicles produced by Aggregatibacter actinomycetemcomitans.

• Neuroscience

  
  Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration Jessica M. Sidisky¹, Daniel T. Babcock^{1 1}Department of Biological Sciences, Lehigh University The goal of this procedure is to dissect the dorsal longitudinal muscle (DLM) tissue to assess the structural integrity of DLM neuromuscular junctions (NMJs) in neurodegenerative disease models using Drosophila melanogaster.

• Bioengineering

  
  Characterizing Single-Molecule Conformational Changes Under Shear Flow with Fluorescence Microscopy Avani V. Pisapati¹, Yi Wang*², Megan E. Blauch*³, Nathan J. Wittenberg³, Xuanhong Cheng^1,2, X. Frank Zhang^{1,4 1}Department of Bioengineering, Lehigh University, ²Department of Materials Science and Engineering, Lehigh University, ³Department of Chemistry, Lehigh University, ⁴Department of Mechanical Engineering and Mechanics, Lehigh University We present a protocol for immobilizing single macromolecules in microfluidic devices and quantifying changes in their conformations under shear flow. This protocol is useful for characterizing the biomechanical and functional properties of biomolecules such as proteins and DNA in a flow environment.

• Cancer Research

  
  Longitudinal Morphological and Physiological Monitoring of Three-dimensional Tumor Spheroids Using Optical Coherence Tomography Yongyang Huang¹, Jinyun Zou¹, Mudabbir Badar¹, Junchao Liu¹, Wentao Shi⁵, Shunqiang Wang², Qiongyu Guo³, Xiaofang Wang¹, Sarah Kessel⁴, Leo Li-Ying Chan⁴, Peter Li⁴, Yaling Liu^2,5, Jean Qiu⁴, Chao Zhou^{1,5,6 1}Department of Electrical and Computer Engineering, Lehigh University, ²Department of Mechanical Engineering, Lehigh University, ³Department of Biomedical Engineering, Southern University of Science and Technology, ⁴Department of Technology R&D, Nexcelom Bioscience LLC, ⁵Department of Bioengineering, Lehigh University, ⁶Center for Photonics and Nanoelectronics, Lehigh University Optical coherence tomography (OCT), a three-dimensional imaging technology, was used to monitor and characterize the growth kinetics of multicellular tumor spheroids. Precise volumetric quantification of tumor spheroids using a voxel counting approach, and label-free dead tissue detection in the spheroids based on intrinsic optical attenuation contrast, were demonstrated.

• Engineering

  
  Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions Matthew D. Wehrman¹, Melissa J. Milstrey¹, Seth Lindberg², Kelly M. Schultz^{1 1}Department of Chemical and Biomolecular Engineering, Lehigh University, ²Process and Engineering Development, Procter & Gamble Co. We demonstrate the fabrication and use of a microfluidic device that enables multiple particle tracking microrheology measurements to study the rheological effects of repeated phase transitions on soft matter.

• Genetics

  
  Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity Sara Lynn N. Farwell¹, Joshua B. Slee², Yaqiu Li¹, Linda J. Lowe-Krentz^{1 1}Department of Biological Sciences, Lehigh University, ²Department of Natural Science, DeSales University A construct encoding TMEM184A with a GFP tag at the carboxy-terminus designed for eukaryotic expression, was employed in assays designed to confirm the identification of TMEM184A as a heparin receptor in vascular cells.

• Biology

  
  Drosophila Preparation and Longitudinal Imaging of Heart Function In Vivo Using Optical Coherence Microscopy (OCM) Jing Men^1,2, Jason Jerwick^2,3, Penghe Wu^1,2, Mingming Chen^3,4, Aneesh Alex^2,3, Yutao Ma⁴, Rudolph E. Tanzi⁵, Airong Li⁵, Chao Zhou^{1,2,3 1}Bioengineering Program, Lehigh University, ²Center for Photonics and Nanoelectronics, Lehigh University, ³Department of Electrical and Computer Engineering, Lehigh University, ⁴State Key Laboratory of Software Engineering, Wuhan University, ⁵Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School Here, the experimental protocols are described for preparing Drosophila at different developmental stages and performing longitudinal optical imaging of Drosophila heartbeats using a custom optical coherence microscopy (OCM) system. The cardiac morphological and dynamical changes can be quantitatively characterized by analyzing the heart structural and functional parameters from OCM images.

• Chemistry

  
  Fluorescence-based Monitoring of PAD4 Activity via a Pro-fluorescence Substrate Analog Mary J. Sabulski¹, Jonathan M. Fura¹, Marcos M. Pires^{1 1}Department of Chemistry, Lehigh University PAD4 is an enzyme responsible for the conversion of peptidyl-arginine to peptidyl-citrulline. Dysregulation of PAD4 has been implicated in a number of human diseases. A facile and high-throughput compatible fluorescence based PAD4 assay is described.

• Chemistry

  
  Preparation and Use of Samarium Diiodide (SmI₂) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction Dhandapani V. Sadasivam¹, Kimberly A. Choquette¹, Robert A. Flowers II^{1 1}Department of Chemistry, Lehigh University A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.