George Mason University View Institution's Website 12 articles published in JoVE Behavior Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice Caroline L.C. Neely1, Karin A. Pedemonte1, Katelyn N. Boggs1, Jane M. Flinn1 1Department of Psychology, Cognitive Behavioral Neuroscience, George Mason University Here, we present a protocol to quantify nest building behavior in mice, which is known to be impaired in several neurological disorders and diseases. This protocol examines the utility of four materials and offers the opportunity to quantify the rater agreement in scoring, improving the validity and reliability of the assay. Immunology and Infection Purification of High Yield Extracellular Vesicle Preparations Away from Virus Catherine DeMarino*1, Robert A. Barclay*1, Michelle L. Pleet1, Daniel O. Pinto1, Heather Branscome1,2, Siddhartha Paul3, Benjamin Lepene4, Nazira El-Hage5, Fatah Kashanchi1 1Laboratory of Molecular Virology, School of Systems Biology, George Mason University, 2American Type Culture Collection (ATCC), 3ATCC Cell Systems, 4Ceres Nanosciences, Inc, 5Department of Immunology and Nano-medicine, Herbert Wertheim College of Medicine, Florida International University This protocol isolates extracellular vesicles (EVs) away from virions with high efficiency and yield by incorporating EV precipitation, density gradient ultracentrifugation, and particle capture to allow for a streamlined workflow and a reduction of starting volume requirements, resulting in reproducible preparations for use in all EV research. Chemistry Characterizing Electron Transport through Living Biofilms Matthew Yates1, Sarah Strycharz-Glaven1, Joel Golden1, Jared Roy1,2, Stanislav Tsoi3, Jeffrey Erickson1, Mohamed El-Naggar4, Scott Calabrese Barton5, Leonard Tender1 1Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 2George Mason University, 3Chemistry Division, Naval Research Laboratory, 4Departments of Physics, Biological Sciences, and Chemistry, University of Southern California, 5Department of Chemical Engineering and Materials Science, Michigan State University A protocol for measuring electrical conductivity of living microbial biofilms under physiologically relevant conditions is presented. Neuroscience Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays Monica L. Gertz1, Zachary Baker2, Sharon Jose3, Nathalia Peixoto4 1Krasnow Institute for Advanced Study, George Mason University, 2Neural Engineering, Bioengineering, George Mason University, 3Neural Engineering, Computer Science, George Mason University, 4Electrical and Computer Engineering, George Mason University Mouse neuronal cells cultured on multi-electrode arrays display an increase in response following electrical stimulation. This protocol demonstrates how to culture neurons, how to record activity, and how to establish a protocol to train the networks to respond to patterns of stimulation. Biology Non-enzymatic, Serum-free Tissue Culture of Pre-invasive Breast Lesions for Spontaneous Generation of Mammospheres Virginia Espina1, Kirsten H. Edmiston2, Lance A. Liotta1 1Center for Applied Proteomics and Molecular Medicine, George Mason University, 2Virginia Surgery Associates Primary cell culture using intact tissue organoids provides a model system that mimics the multi-cellular in vivo microenvironment. We developed a serum-free primary breast epithelium tissue culture model that perpetuates mixed cell culture lineages and exhibits differentiated morphology, without enzymatic tissue disruption. Breast organoids remain viable for >6 months. Immunology and Infection Viral Concentration Determination Through Plaque Assays: Using Traditional and Novel Overlay Systems Alan Baer1, Kylene Kehn-Hall1 1National Center for Biodefense and Infectious Diseases, George Mason University Plaque assays are the gold standard for viral quantification, utilizing entrapping overlays on host cellular monolayers to determine viral titers. While various semisolid overlays have traditionally been used, here we demonstrate plaque techniques comparing semisolid overlays to a novel liquid microcrystalline cellulose among several families of viruses. Bioengineering Hydrogel Nanoparticle Harvesting of Plasma or Urine for Detecting Low Abundance Proteins Ruben Magni*1, Benjamin H. Espina*2, Lance A. Liotta1, Alessandra Luchini1, Virginia Espina1 1Center for Applied Proteomics and Molecular Medicine, George Mason University, 2Ceres Nanosciences Several pathological biomarkers cannot be easily detected by current techniques because of their low concentration in biological fluids, the presence of degrading enzymes, and large amounts of high molecular weight proteins. Chemically functionalized hydrogel nanoparticles can harvest, preserve and concentrate low abundance proteins enabling the detection of previously undetectable biomarkers. Medicine A Novel Application of Musculoskeletal Ultrasound Imaging Avinash Eranki1, Nelson Cortes2, Zrinka Gregurić Ferenček3, Siddhartha Sikdar4 1Department of Electrical and Computer Engineering, George Mason University, 2Sports Medicine Assessment, Research & Testing Laboratory, George Mason University, 3School of Physics, Astronomy, and Computational Sciences, George Mason University, 4Department of Bioengineering, George Mason University We describe a new ultrasound-based vector tissue Doppler imaging technique to measure muscle contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities. This approach provides complementary measurements of dynamic muscle function and could lead to a better understanding of mechanisms underlying musculoskeletal disorders. Biology Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks Rohini Mehta1,2, Ancha Baranova1,2,3, Aybike Birerdinc1,2 1Molecular and Microbiology Department and Center for the Study of Genomics in Liver Diseases, George Mason University, 2Translational Research Institute, Inova Health System, 3Research Center for Medical Genetics RAMS Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy. Immunology and Infection Specific Marking of HIV-1 Positive Cells using a Rev-dependent Lentiviral Vector Expressing the Green Fluorescent Protein Jia Guo*1, Clinton Enos*1, Yuntao Wu1 1National Center for Biodefense and Infectious Diseases, Department of Molecular and Microbiology, George Mason University We have developed a lentiviral vector that possesses, in addition to the Tat-responsive LTR, the Rev-response element (RRE) that can regulate reporter gene expression in an HIV-1 Tat- and Rev-dependent fashion. The vector permits the specific detection of replicating HIV in living cells via the expression of GFP. Neuroscience Laser Capture Microdissection of Drosophila Peripheral Neurons Eswar Prasad R. Iyer1,2, Daniel N. Cox1,2 1Department of Molecular and Microbiology, George Mason University, 2Krasnow Institute for Advanced Study, George Mason University In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses. Biology Isolation and Purification of Drosophila Peripheral Neurons by Magnetic Bead Sorting Eswar Prasad R. Iyer1,2, Srividya Chandramouli Iyer1,2, Mikolaj J. Sulkowski1,2, Daniel N. Cox1,2 1Department of Molecular and Microbiology, George Mason University, 2Krasnow Institute for Advanced Study, George Mason University In this video-article we present a method for the isolation and purification of Drosophila peripheral neurons using a fast magnetic bead assisted cell sorting strategy. RNA obtained from the isolated cells can be readily used for downstream applications including microarray analyses.