University of Arkansas 14 articles published in JoVE Biology An Adapted Optical Density-Based Microplate Assay for Characterizing Actinobacteriophage Infection Elijah I. Christenson1, Qingyang Zhang2, Ruth Plymale1 1Department of Biology, Ouachita Baptist University, 2Department of Mathematical Sciences, University of Arkansas An optical density-based microplate method is described to quantify long-term bacterial growth in the presence of bacteriophages, suitable for actinomycetes and other slow-growing bacteria. This method includes modifications to reduce evaporation and lid condensation and R code to calculate virus infection metrics, including the area under the curve, growth maximum, and relative virulence. Developmental Biology Using Expansion Microscopy to Physically Enlarge Whole-Mount Drosophila Embryos for Super-Resolution Imaging Samia Parveen1, Nicolas W. Jones1, Ian Millerschultz1, Adam C. Paré1 1Department of Biological Sciences, University of Arkansas Here, a protocol for the implementation of expansion microscopy in early Drosophila embryos to achieve super-resolution imaging using a conventional laser-scanning confocal microscope is presented. Engineering Micromechanical Tension Testing of Additively Manufactured 17-4 PH Stainless Steel Specimens David Gonzalez-Nino1, Steven Sonntag2, Mahyar Afshar-Mohajer2, Josh Goss2, Min Zou2, Gary S. Prinz1 1Department of Civil Engineering, University of Arkansas, 2Department of Mechanical Engineering, University of Arkansas Presented here is a procedure for measuring fundamental material properties through micromechanical tension testing. Described are the methods for micro-tensile specimen fabrication (allowing rapid micro-specimen fabrication from bulk material volumes by combining photolithography, chemical etching, and focused ion beam milling), indenter tip modification, and micromechanical tension testing (including an example). Engineering Terahertz Imaging and Characterization Protocol for Freshly Excised Breast Cancer Tumors Nagma Vohra*1, Tyler Bowman*1, Keith Bailey2, Magda El-Shenawee1 1Department of Electrical Engineering, University of Arkansas, 2Oklahoma Animal Disease Diagnostic Laboratory, Oklahoma State University Freshly excised human breast cancer tumors are characterized with terahertz spectroscopy and imaging following fresh tissue handling protocols. Tissue positioning is taken into consideration to enable effective characterization while providing analysis in a timely manner for future intraoperative applications. Developmental Biology Genotyping of Sea Anemone during Early Development Miguel A.P. Silva1, Nagayasu Nakanishi1 1Department of Biological Sciences, University of Arkansas The goal of this protocol is to genotype the sea anemone Nematostella vectensis during gastrulation without sacrificing the embryo. Environment Measuring Stolons and Rhizomes of Turfgrasses Using a Digital Image Analysis System Cristina Pornaro1, Stefano Macolino1, Michael D. Richardson1 1Department of Agronomy, Food, Natural Resources, Animals, and Environment, University of Padova, 2Department of Horticulture, University of Arkansas A software-based image analysis system provides an alternative method to study the morphology of stoloniferous and rhizomatous species. This protocol permits measurement of the length and diameter of stolons and rhizomes and can be applied to samples with a large amount of biomass and to a wide variety of species. Environment Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L. Kanniah Rajasekaran1, Ronald J. Sayler2, Rajtilak Majumdar1, Christine M. Sickler1, Jeffrey W. Cary1 1Southern Regional Research Center, USDA-ARS, Food and Feed Safety Research Unit, 2Department of Plant Pathology, University of Arkansas Here we present a protocol to analyze Aspergillus flavus growth and aflatoxin production in maize kernels expressing an antifungal protein. Using a GFP-expressing A. flavus strain we monitored the infection and spread of the fungus in mature kernels in real time. The assay is rapid, reliable, and reproducible. Bioengineering Production of Extracellular Matrix Fibers via Sacrificial Hollow Fiber Membrane Cell Culture Kevin Roberts1, John Taehwan Kim2, Shelby White2, Jamie Hestekin3, Jeffrey C. Wolchok2 1Cell & Molecular Biology Program, University of Arkansas, 2Department of Biomedical Engineering, University of Arkansas, 3Ralph E. Martin Department of Biomedical Engineering, University of Arkansas The goal of this protocol is production of whole extracellular matrix fibers targeted for wound repair which are suitable for preclinical evaluation as part of a regenerative scaffold implant. These fibers are produced by the culture of fibroblasts on hollow fiber membranes and extracted by dissolution of the membranes. Chemistry Exfoliation and Analysis of Large-area, Air-Sensitive Two-Dimensional Materials Josh P. Thompson1, M. Hasan Doha1, Peter Murphy1,2, Jin Hu1,3, Hugh O.H. Churchill1,3 1Department of Physics, University of Arkansas, 2Department of Physics, SUNY Geneseo, 3Institute for Nanoscale Science and Engineering, University of Arkansas A method for exfoliating large thin flakes of air sensitive two-dimensional materials and safely transporting them for analysis outside of a glovebox is presented. Behavior Using the Visual World Paradigm to Study Sentence Comprehension in Mandarin-Speaking Children with Autism Peng Zhou*1, Weiyi Ma*2, Likan Zhan*3, Huimin Ma*4 1Department of Foreign Languages and Literatures, Tsinghua University, 2School of Human Environmental Sciences, University of Arkansas, 3Institute for Speech Pathology and the Brain Science, Beijing Language and Culture University, 4Department of Electronic Engineering, Tsinghua University We present a protocol to examine the use of morphological cues during real-time sentence comprehension by children with autism. Immunology and Infection A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli Sumana Venkat1,2, Caroline Gregory3, Kexin Meng4, Qinglei Gan1, Chenguang Fan1,2 1Department of Chemistry and Biochemistry, University of Arkansas, 2Cell and Molecular Biology Program, University of Arkansas, 3Department of Biological Sciences, University of Arkansas, 4Fayetteville High School Genetic code expansion serves as a powerful tool to study a wide range of biological processes, including protein acetylation. Here we demonstrate a facile protocol to exploit this technique for generating homogeneously acetylated proteins at specific sites in Escherichia coli cells. Developmental Biology Isolation of Endothelial Progenitor Cells from Human Umbilical Cord Blood Prashanth Ravishankar1, M. Alejandra Zeballos1, Kartik Balachandran1 1Department of Biomedical Engineering, University of Arkansas The goal of this protocol is to isolate endothelial progenitor cells from umbilical cord blood. Some of the applications include using these cells as a biomarker for identifying patients with cardiovascular risk, treating ischemic diseases, and creating tissue-engineered vascular and heart valve constructs. Bioengineering Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis Gage J. Greening1, Narasimhan Rajaram1, Timothy J. Muldoon1 1Department of Biomedical Engineering, University of Arkansas The assembly and use of a multimodal microendoscope is described which can co-register superficial tissue image data with tissue physiological parameters including hemoglobin concentration, melanin concentration, and oxygen saturation. This technique can be useful for evaluating tissue structure and perfusion, and can be optimized for individual needs of the investigator. Environment Tracking Microbial Contamination in Retail Environments Using Fluorescent Powder - A Retail Delicatessen Environment Example Sujata A. Sirsat1, Kawon Kim1, Kristen E. Gibson2, Phillip G. Crandall2, Steven C. Ricke2, Jack A. Neal1 1Conrad N. Hilton College of Hotel and Restaurant Management, University of Houston, 2Center for Food Safety, Department of Food Science, University of Arkansas The overall goal of this study was to demonstrate the potential cross contamination mechanism of foodborne pathogen Listeria monocytogenes in a retail deli setting. This methodology may be applied to a variety of different environments to track pathogen contamination.
