University of California, Davis

80 articles published in JoVE

• Biology

  
  Isolation of Small Preantral Follicles from the Bovine Ovary Using a Combination of Fragmentation, Homogenization, and Serial Filtration Stephanie P. McDonnell¹, Juliana I. Candelaria¹, Amanda J. Morton¹, Anna C. Denicol^{1 1}Department of Animal Science, University of California Davis Advancing the study of preantral folliculogenesis requires efficient methods of follicle isolation from single ovaries. Presented here is a streamlined, mechanical protocol for follicle isolation from bovine ovaries using a tissue chopper and homogenizer. This method allows collection of a large number of viable preantral follicles from a single ovary.

• Genetics

  
  Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae Diedre Reitz¹, Jérôme Savocco², Aurèle Piazza², Wolf-Dietrich Heyer^{1,3 1}Department of Microbiology & Molecular Genetics, University of California, Davis, ²Laboratory of Biology & Modeling of the Cell, École Normale Supérieure de Lyon, ³Department of Molecular & Cellular Biology, University of California, Davis The D-loop capture (DLC) and D-loop extension (DLE) assays utilize the principle of proximity ligation together with quantitative PCR to quantify D-loop formation, D-loop extension, and product formation at the site of an inducible double-stranded break in Saccharomyces cerevisiae.

• Genetics

  
  Development of Knock-Out Muscle Cell Lines using Lentivirus-Mediated CRISPR/Cas9 Gene Editing Mathilde Beaufils¹, Amandine Tourel¹, Anne Petiot¹, Nicole B. Halmai², Dave J. Segal², John Rendu¹, Isabelle Marty^{1 1}University Grenoble Alpes, INSERM, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, ²Genome Center, University of California, Davis The protocol describes how to generate knock-out myoblasts using CRISPR/Cas9, starting from the design of guide-RNAs to the cellular cloning and characterization of the knock-out clones.

• Neuroscience

  
  AAV Deployment of Enhancer-Based Expression Constructs In Vivo in Mouse Brain Tracy L. Warren^1,2, Jason T. Lambert^1,2, Alex S. Nord^{1,2 1}Department of Psychiatry and Behavioral Sciences, University of California, Davis, ²Department of Neurobiology, Physiology and Behavior, University of California, Davis This protocol describes a novel rAAV-based transient enhancer-reporter assay. This assay can be used to induce enhancer-driven expression in vivo in the mouse brain.

• Biology

  
  A Magnetic-Bead-Based Mosquito DNA Extraction Protocol for Next-Generation Sequencing Tse-Yu Chen¹, Adam E. Vorsino², Kyle J. Kosinski¹, Ana L. Romero-Weaver¹, Eva A. Buckner¹, Joanna C. Chiu³, Yoosook Lee^{1 1}Florida Medical Entomology Laboratory, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences, University of Florida, ²U. S. Fish and Wildlife Service, Pacific Islands Fish and Wildlife Office, ³Department of Entomology and Nematology, University of California Davis Described here is a DNA extraction protocol using magnetic beads to produce high quality DNA extractions from mosquitoes. These extractions are suitable for a downstream next-generation sequencing approach.

• Biochemistry

  
  Isolation of Histone from Sorghum Leaf Tissue for Top Down Mass Spectrometry Profiling of Potential Epigenetic Markers Mowei Zhou¹, Shadan H. Abdali¹, David Dilworth², Lifeng Liu², Benjamin Cole², Neha Malhan¹, Amir H. Ahkami¹, Tanya E. Winkler¹, Joy Hollingsworth³, Julie Sievert³, Jeff Dahlberg³, Robert Hutmacher^4,5, Mary Madera⁶, Judith A. Owiti⁶, Kim K. Hixson¹, Peggy G. Lemaux⁶, Christer Jansson¹, Ljiljana Paša-Tolić^{1 1}Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, ²DOE-Joint Genome Institute, Lawrence Berkeley Laboratory, ³Kearney Agricultural Research and Extension Center, University of California Agriculture and Natural Resources, ⁴West Side Research and Extension Center, University of California, ⁵Department of Plant Sciences, University of California, Davis, ⁶Department of Plant and Microbial Biology, University of California, Berkeley The protocol has been developed to effectively extract intact histones from sorghum leaf materials for profiling of histone post-translational modifications that can serve as potential epigenetic markers to aid engineering drought resistant crops.

• Immunology and Infection

  
  TurboID-Based Proximity Labeling for In Planta Identification of Protein-Protein Interaction Networks Yongliang Zhang*¹, Yuanyuan Li*^2,3, Xinxin Yang¹, Zhiyan Wen¹, Ugrappa Nagalakshmi², Savithramma P. Dinesh-Kumar^{2,3 1}State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, ²Department of Plant Biology, College of Biological Sciences, University of California, Davis, ³Genome Center, College of Biological Sciences, University of California, Davis Described here is a proximity labeling method for identification of interaction partners of the TIR domain of the NLR immune receptor in Nicotiana benthamiana leaf tissue. Also provided is a detailed protocol for the identification of interactions between other proteins of interest using this technique in Nicotiana and other plant species.

• Immunology and Infection

  
  Identification of Neutrophil Extracellular Traps in Paraffin-Embedded Feline Arterial Thrombi using Immunofluorescence Microscopy Laetitia Duler¹, Nghi Nguyen², Eric Ontiveros³, Ronald H. L. Li^{2 1}Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, ²Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, ³Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis We describe a method to identify neutrophil extracellular traps (NETs) in formaldehyde-fixed and paraffin-embedded feline cardiogenic arterial thrombi using heat-induced antigen retrieval and a double immunolabeling protocol.

• Genetics

  
  Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes Yana P. Blokhina^1,2, Ivan Olaya^1,2, Sean M. Burgess^{1 1}Department of Molecular and Cellular Biology, University of California, Davis, ²Integrative Genetics and Genomics Graduate Group, University of California, Davis Nuclear surface spreads are an indispensable tool for studying chromosome events during meiosis. Here we demonstrate a method to prepare and visualize meiotic chromosomes during prophase I from zebrafish spermatocytes.

• Neuroscience

  
  Reliable Isolation of Central Nervous System Microvessels Across Five Vertebrate Groups Yinyu Yuan*¹, Jacquelyn R. Dayton*¹, Marie-Lena Freese², Bryce G. Dorflinger¹, Lillian Cruz-Orengo^{1 1}Department of Anatomy, Physiology and Cell Biology, University of California Davis, ²University of Veterinary Medicine Hannover Foundation The goal of this protocol is to isolate microvessels from multiple regions of the central nervous system of lissencephalic and gyrencephalic vertebrates.

• Bioengineering

  
  Prospecting Microbial Strains for Bioremediation and Probiotics Development for Metaorganism Research and Preservation Helena D. M. Villela¹, Caren L. S. Vilela¹, Juliana M. Assis¹, Natascha Varona², Camille Burke², David A. Coil², Jonathan A. Eisen², Raquel S. Peixoto^{1,2,3 1}LEMM, Laboratory of Molecular Microbial Ecology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro (UFRJ), ²Genome Center, University of California, Davis, ³IMAM-AquaRio - Rio de Janeiro Aquarium Research Center Pollution affects all biomes. Marine environments have been particularly impacted, especially coral reefs, one of the most sensitive ecosystems on Earth. Bioremediation is the capacity of organisms to degrade contaminants. Here, we describe methodologies to isolate and test microbes presenting bioremediation ability and potential probiotic characteristics for corals.

• Biochemistry

  
  A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products Katherine M. Murphy¹, Siwon Chung¹, Shruti Fogla¹, Hana B. Minsky¹, Karen Yong Zhu¹, Philipp Zerbe^{1 1}Department of Plant Biology, University of California Davis Here we present easy to use protocols for producing and purifying diterpenoid metabolites through the combinatorial expression of biosynthetic enzymes in Escherichia coli or Nicotiana benthamiana, followed by chromatographic product purification. The resulting metabolites are suitable for various studies including molecular structure characterization, enzyme functional studies, and bioactivity assays.

• Environment

  
  PARbars: Cheap, Easy to Build Ceptometers for Continuous Measurement of Light Interception in Plant Canopies William T. Salter¹, Andrew M. Merchant¹, Matthew E. Gilbert², Thomas N. Buckley^{2 1}School of Life and Environmental Sciences, Sydney Institute of Agriculture, University of Sydney, ²Department of Plant Sciences, University of California, Davis Here, we present detailed instructions on how to build and calibrate research quality ceptometers (light sensors that integrate light intensity across many sensors arrayed linearly along a horizontal bar).

• Immunology and Infection

  
  A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection Leif S. Anderson¹, Mack B. Reynolds¹, Kathryn R. Rivara¹, Lloyd S. Miller², Scott I. Simon^{1 1}Department of Biomedical Engineering, University of California Davis, ²Department of Dermatology, Johns Hopkins University School of Medicine An approach is described for real-time detection of the innate immune response to cutaneous wounding and Staphylococcus aureus infection of mice. By comparing LysM-EGFP mice (which possess fluorescent neutrophils) with a LysM-EGFP crossbred immunodeficient mouse strain, we advance our understanding of infection and the development of approaches to combat infection.

• Environment

  
  Improving Infrared Spectroscopy Characterization of Soil Organic Matter with Spectral Subtractions Andrew J. Margenot¹, Sanjai J. Parikh², Francisco J. Calderón^{3 1}Department of Crop Sciences, University of Illinois Urbana-Champaign, ²Department of Land, Air and Water Resources, University of California Davis, ³Central Great Plains Resources Management Research, USDA ARS SOM underlies many soil functions and processes, but its characterization by FTIR spectroscopy is often challenged by mineral interferences. The described method can increase the utility of SOM analysis by FTIR spectroscopy by subtracting mineral interferences in soil spectra using empirically obtained mineral reference spectra.

• Biochemistry

  
  Measuring Liver Mitochondrial Oxygen Consumption and Proton Leak Kinetics to Estimate Mitochondrial Respiration in Holstein Dairy Cattle Heidi A. Rossow¹, Gabriela Acetoze², John Champagne¹, Jon J. Ramsey^{3 1}Veterinary Medicine Teaching and Research Center, University of California Davis, ²Archer Daniels Midland, ³Department of Molecular Biosciences, University of California Davis Here, we share methods for measuring mitochondrial oxygen consumption, a defining concept of nutritional energetics, and proton leak, the primary cause of inefficiency in mitochondrial generation of ATP. These results can account for 30% of the energy lost in nutrient utilization to help evaluate mitochondrial function.

• Environment

  
  An Optimized Rhizobox Protocol to Visualize Root Growth and Responsiveness to Localized Nutrients Jennifer E. Schmidt¹, Carolyn Lowry², Amelie C.M. Gaudin^{1 1}Department of Plant Sciences, University of California at Davis, ²Department of Natural Resources and the Environment, University of New Hampshire Visualizing and measuring root growth in situ is extremely challenging. We present a customizable rhizobox method to track root development and proliferation over time in response to nutrient enrichment. This method is used to analyze maize genotypic differences in root plasticity in response to an organic nitrogen source.

• Biochemistry

  
  Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays Anthony Asher¹, Iniyan Ganesan¹, Laura Klasek¹, Steven M. Theg^{1 1}Department of Plant Biology, University of California - Davis We present protocols herein for high-yield isolation of physiologically active thylakoids and protein transport assays for the chloroplast twin arginine translocation (cpTat), secretory (cpSec1), and signal recognition particle (cpSRP) pathways.

• Immunology and Infection

  
  In Vitro Canine Neutrophil Extracellular Trap Formation: Dynamic and Quantitative Analysis by Fluorescence Microscopy Ronald H.L. Li¹, Fern Tablin^{2 1}Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, ²Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis We describe methods to isolate canine neutrophils from whole blood and visualize NET formation in live neutrophils using fluorescence microscopy. Also described are protocols to quantify NET formation and citrullinated histone H3 (citH3) expression using immunofluorescence microscopy.

• Medicine

  
  An In Vitro Approach to Photodynamic Therapy Evan Austin^1,2, Jared Jagdeo^{1,2,3 1}Department of Dermatology, University of California, Davis, ²Dermatology Service, Sacramento VA Medical Center, ³Department of Dermatology, State University of New York, Downstate Medical Center Photodynamic therapy (PDT) is a medical procedure that involves incubation of an exogenously applied photosensitizer (PS) followed by visible light photoactivation to induce apoptosis. We present an in vitro PDT protocol designed to simulate PDT that may be used to study differences in PS incubation and light treatment parameters.

• Medicine

  
  The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation Payam Vali*¹, Sylvia Gugino*², Carmon Koenigsknecht², Justin Helman², Praveen Chandrasekharan², Munmun Rawat², Satyan Lakshminrusimha¹, Jayasree Nair^{2 1}Department of Pediatrics, University of California Davis, ²Department of Pediatrics, University at Buffalo Invasive instrumentation of the fetal lamb provides accurate physiologic measurements of the transitioning circulation in a model that closely mimics the newly born infant.

• Bioengineering

  
  Surface Functionalization of Hepatitis E Virus Nanoparticles Using Chemical Conjugation Methods Chun Chieh Chen*¹, Marie Stark*¹, Mo Baikoghli¹, R. Holland Cheng^{1 1}Department of Molecular and Cellular Biology, University of California Davis We have engineered the capsid protein of hepatitis E virus as a theranostic nanoparticle (HEVNP). HEVNP self-assembles into a stable icosahedral cage in mucosal delivery. Here, we describe the modification of HEVNPs for tumor targeting by mutating surface-exposed residues to cysteines, which conjugate synthetic ligands that specifically bind tumor cells.

• Biology

  
  In Vitro SUMOylation Assay to Study SUMO E3 Ligase Activity Wan-Shan Yang¹, Mel Campbell², Hsing-Jien Kung^2,3,4,5, Pei-Ching Chang^{1,6 1}Institute of Microbiology and Immunology, National Yang-Ming University, ²UC Davis Cancer Center, University of California, Davis, ³Department of Biochemistry and Molecular Medicine, University of California, Davis, ⁴Institute for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, ⁵Division of Molecular and Genomic Medicine, National Health Research Institutes, ⁶Center for Infectious Disease and Cancer Research, Kaohsiung Medical University Unlike ubiquitin ligases, few E3 SUMO ligases have been identified. This modified in vitro SUMOylation protocol is able to identify novel SUMO E3 ligases by an in vitro reconstitution assay.

• Biology

  
  Functional Imaging of Viral Transcription Factories Using 3D Fluorescence Microscopy Christopher P. Chen¹, Frank Chuang², Yoshihiro Izumiya^{1 1}Department of Dermatology, University of California Davis School of Medicine, University of California, Davis, ²Center for Biophotonics, Department of Biochemistry and Molecular Medicine, University of California, Davis Viral transcriptional factories are discrete structures that are enriched with cellular RNA polymerase II to increase viral gene transcription during reactivation. Here, a method to locate sites of actively transcribing viral chromatin in 3D nuclear space by a combination of immunofluorescence staining and in situ RNA hybridization is described.

• Environment

  
  Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas Yong-Biao Liu¹, Xiangbing Yang², Tiffany Masuda^{1 1}Crop Improvement and Protection Unit, USDA-ARS, ²The University of California Davis This paper describes nitric oxide (NO) fumigation protocols for postharvest pest control. Fumigation chambers are flushed with nitrogen (N2) to establish ultralow oxygen conditions before NO is injected. At the end, chambers are flushed with N2 to dilute NO before exposing products to ambient air to prevent exposure to NO2.

• Behavior

  
  Profiling Anti-Neu5Gc IgG in Human Sera with a Sialoglycan Microarray Assay Shani Leviatan Ben-Arye¹, Hai Yu², Xi Chen², Vered Padler-Karavani^{1 1}Department of Cell Research and Immunology, Tel Aviv University, ²Department of Chemistry, University of California-Davis A sialoglycan microarray assay can be used to evaluate anti-Neu5Gc antibodies in human sera, making it a potential high-throughput diagnostic assay for cancer and other chronic inflammation-mediated human diseases.

• Bioengineering

  
  Treatment of Ligament Constructs with Exercise-conditioned Serum: A Translational Tissue Engineering Model Ann Lee-Barthel¹, Keith Baar^1,2, Daniel W. D. West^{1,3 1}Department of Neurobiology, Physiology, and Behavior, University of California, Davis, ²Department of Physiology and Membrane Biology, University of California, Davis, ³Faculty of Kinesiology and Physical Education, University of Toronto We present a model of ligament tissue in which three-dimensional constructs are treated with the human exercise-conditioned serum and analyzed for collagen content, function, and cellular biochemistry.

• Environment

  
  Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff Brian S. Anderson^1,2, Bryn M. Phillips^1,2, Jennifer P. Voorhees^1,2, Michael Cahn^{3 1}Department of Environmental Toxicology, University of California, Davis, ²Marine Pollution Studies Laboratory - Granite Canyon, ³University of California, Cooperative Extension, Monterey County This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

• Engineering

  
  Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals Lauren A. Hughes¹, Klaus van Benthem^{1 1}Department of Materials Science and Engineering, University of California, Davis A viable technique for the formation of strontium titanate bicrystals at high pressure and fast heating rate via the spark plasma sintering apparatus is developed.

• Biochemistry

  
  A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles Yuanpei Li^1,2, Gaurav Bharadwaj¹, Joyce S. Lee^{3 1}Department of Biochemistry & Molecular Medicine, University of California, Davis, ²UC Davis Comprehensive Cancer Center, University of California, Davis, ³Department of Internal Medicine, Division of Hematology and Oncology, University of California, Davis To deliver cancer drugs to tumor sites with high specificity and reduced side effects, new methods based on nanoparticles are required. Here, we describe disulfide cross-linked micelles that can be easily prepared by hydrogen peroxide-mediated oxidation and are able to dissociate efficiently under a reducing tumor environment to release payloads.

• Genetics

  
  The Use of Induced Somatic Sector Analysis (ISSA) for Studying Genes and Promoters Involved in Wood Formation and Secondary Stem Development Antanas Spokevicius¹, Lynette Taylor¹, Emma Melder¹, Kim Van Beveren¹, Josquin Tibbits², Nicky Creux^3,4, Gerd Bossinger^{1 1}School of Ecosystem and Forest Sciences, Faculty of Science, The University of Melbourne, ²Victorian AgriBiosciences Centre, La Trobe University R&D Park, ³College of Biological Sciences, Department of Plant Biology, University of California, Davis, ⁴Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria Here we present a protocol that facilitates the medium to high throughput functional characterization of gene and promoter constructs in tree secondary stem tissue within comparatively short time frames. It is efficient, easy to use and widely applicable to a range of tree species.

• Genetics

  
  Laser-assisted Cytoplasmic Microinjection in Livestock Zygotes Yanina S. Bogliotti¹, Marcela Vilarino¹, Pablo J. Ross^{1 1}Department of Animal Science, University of California, Davis This protocol shows how to perform cytoplasmic microinjection in farm animal zygotes. This technique can be used to deliver any solution into the one-cell embryo such as genome editing tools to generate knockout animals.

• Immunology and Infection

  
  Visualization of Twitching Motility and Characterization of the Role of the PilG in Xylella fastidiosa Xiangyang Shi¹, Hong Lin^{2 1}Department of Plant Science, University of California, Davis, ²Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, United States Department of Agriculture In this study, a nano-microfluidic flow chamber was employed to visualize and functionally characterize the twitching motility of Xylella fastidiosa, a bacterium that causes Pierce's disease in grapevine.

• Biology

  
  Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1 Demet Candas¹, Lili Qin¹, Ming Fan¹, Jian-Jian Li^{1 1}Radiation Oncology, University of California, Davis Here, we outline how to study mitochondrial localization of a (cell cycle) kinase, and how to determine its sub-mitochondrial location as well as potential mitochondrial substrates/targets. Forced expression of proteins into the mitochondria provides a useful tool for studying the functional consequences of mitochondrial localization of a protein of interest.

• Medicine

  
  Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia Yu Ouyang¹, Martin S. Judenhofer¹, Jeffrey H. Walton^1,2, Jan Marik³, Simon P. Williams³, Simon R. Cherry^{1,4 1}Department of Biomedical Engineering, University of California, Davis, ²Nuclear Magnetic Resonance Facility, University of California, Davis, ³Biomedical Imaging, Genentech, Inc, ⁴Department of Radiology, University of California, Davis The method presented here uses simultaneous positron emission tomography and magnetic resonance imaging. In the cerebral hypoxia-ischemia model, dynamic changes in diffusion and glucose metabolism occur during and after injury. The evolving and irreproducible damage in this model necessitates simultaneous acquisition if meaningful multi-modal imaging data are to be acquired.

• Biology

  
  Microperfusion Technique to Investigate Regulation of Microvessel Permeability in Rat Mesentery Fitz-Roy E. Curry¹, Joyce F. Clark¹, Roger H. Adamson^{1 1}Department of Physiology & Membrane Biology, University of California Davis The modified Landis technique enables paired measurement of the hydraulic conductivity of individual microvessels in the mesentery of normal and genetically modified rats under control and test conditions using microperfusion techniques. It provides a convenient method to evaluate mechanisms that regulate microvessel permeability and transvascular exchange under physiological conditions.

• Biology

  
  Optical Mapping of Intra-Sarcoplasmic Reticulum Ca²⁺ and Transmembrane Potential in the Langendorff-perfused Rabbit Heart Lianguo Wang¹, Nicole M. De Jesus², Crystal M. Ripplinger^{1 1}Department of Pharmacology, University of California Davis, ²Departments of Pharmacology and Biomedical Engineering, University of California Davis This article describes the detailed protocol and equipment necessary for dual optical mapping of transmembrane potential (Vm) and free intra-sarcoplasmic reticulum (SR) Ca²⁺ in the Langendorff-perfused rabbit heart. This method allows for direct observation and quantification of Vm and SR Ca²⁺ dynamics in the intact heart.

• Biology

  
  Measurement of Extracellular Ion Fluxes Using the Ion-selective Self-referencing Microelectrode Technique Guillaume Luxardi¹, Brian Reid¹, Fernando Ferreira^1,2, Pauline Maillard³, Min Zhao^{1,4 1}Department of Dermatology, Institute for Regenerative Cures, University of California, Davis, ²Departamento de Biologia, Centro de Biologia Molecular e Ambiental, Universidade do Minho, ³Department of Neurology and Center for Neuroscience, University of California, Davis Imaging of Dementia and Aging Laboratory, ⁴Department of Ophthalmology, Institute for Regenerative Cures, University of California, Davis Transporters in cell membranes allow differential segregation of ions across cell membranes or cell layers and play crucial roles during tissue physiology, repair and pathology. We describe the ion-selective self-referencing microelectrode that allows the measurement of specific ion fluxes at single cells and tissues in vivo.

• Medicine

  
  Calibrated Forceps Model of Spinal Cord Compression Injury Ashley McDonough*^1,2, Angela Monterrubio*^1,2, Jeanelle Ariza^1,2, Verónica Martínez-Cerdeño^{1,2 1}Department of Pathology and Laboratory Medicine, University of California, Davis, ²Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children (Northern California) Spinal cord injury models should be highly reproducible. We demonstrate that the calibrated forceps compression model of spinal cord injury is an easy to use surgical method for generating reproducible injuries to the murine spinal cord.

• Biology

  
  A Multi-detection Assay for Malaria Transmitting Mosquitoes Yoosook Lee¹, Allison M. Weakley¹, Catelyn C. Nieman¹, Julia Malvick², Gregory C. Lanzaro^{1 1}Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California - Davis, ²Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis Malaria transmitting mosquitoes have a number of epidemiologically important characteristics that can only be detected using molecular techniques. Utilizing a MALDI-TOF based SNP genotyping platform, we developed an assay for simultaneously detecting multiple key traits (species, insecticide resistance, parasite infection and host choice) of malaria vectors.

• Medicine

  
  Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene Angel Alvarez¹, Gustavo A. Barisone¹, Elva Diaz^{1 1}Department of Pharmacology, University of California, Davis The Focus Formation Assay provides a straightforward method to assess the transforming potential of a candidate oncogene.

• Engineering

  
  A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli Antonio Gomez¹, Robert Pires¹, Alyssa Yambao¹, Valeria La Saponara^{1 1}Department of Mechanical and Aerospace Engineering, University of California, Davis The durability of polymers and fiber-reinforced polymer composites in service is a critical aspect for their designs and condition-based maintenance. We present a novel low-cost laboratory testing platform for the investigation of the influence of concurrent mechanical and environmental loadings, and may help design more efficient yet safer composite structures.

• Biology

  
  Utilizing Custom-designed Galvanotaxis Chambers to Study Directional Migration of Prostate Cells Hsin-ya Yang¹, Thi Dinh La¹, R. Rivkah Isseroff^{1 1}Department of Dermatology, Scool of Medicine, University of California, Davis We present a method to apply a physiological electric field to migrating, immortalized prostate cells in a custom-made galvanotaxis chamber. Using this method, we demonstrate that 2 lines of non-tumorigenic prostate cells demonstrate different degrees of migration directionality in the field.

• Engineering

  
  Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators Joshua Small¹, Adam Fruehling², Anurag Garg³, Xiaoguang Liu¹, Dimitrios Peroulis^{3 1}Department of Electrical and Computer Engineering, University of California, Davis, ²Digital Light Projection (DLP) Technology Development, Texas Instruments, ³Birck Nanotechnology Center and the Department of Electrical and Computer Engineering, Purdue University The robust device design of fringing-field electrostatic MEMS actuators results in inherently low squeeze-film damping conditions and long settling times when performing switching operations using conventional step biasing. Real-time switching time improvement with DC-dynamic waveforms reduces the settling time of fringing-field MEMS actuators when transitioning between up-to-down and down-to-up states.

• Immunology and Infection

  
  High-throughput Assay to Phenotype Salmonella enterica Typhimurium Association, Invasion, and Replication in Macrophages Jing Wu¹, Roberta Pugh¹, Richard C. Laughlin¹, Helene Andrews-Polymenis², Michael McClelland³, Andreas J. Bäumler⁴, L. Garry Adams^{1 1}Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, ²Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M University System Health Science Center, ³University of California, Irvine, ⁴Department of Medical Microbiology & Immunology, School of Medicine, University of California, Davis A high-throughput assay to in vitro phenotype Salmonella or other bacterial association, invasion, and replication in phagocytic cells with high-throughput capacity was developed. The method was employed to evaluate Salmonella gene knockout mutant strains for their involvements in host-pathogen interactions.

• Environment

  
  Colorimetric Paper-based Detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes from Large Volumes of Agricultural Water Bledar Bisha¹, Jaclyn A. Adkins², Jana C. Jokerst³, Jeffrey C. Chandler¹, Alma Pérez-Méndez⁴, Shannon M. Coleman⁴, Adrian O. Sbodio⁵, Trevor V. Suslow⁵, Michelle D. Danyluk⁶, Charles S. Henry², Lawrence D. Goodridge^{7 1}Department of Animal Science, University of Wyoming, ²Department of Chemistry, Colorado State University, ³Department of Environmental and Radiological Health Sciences, Colorado State University, ⁴Department of Animal Sciences, Colorado State University, ⁵Department of Plant Sciences, University of California, Davis, ⁶Department of Food Science and Human Nutrition, Citrus Research and Education Center, University of Florida, ⁷Department of Food Science and Agricultural Chemistry, McGill University A protocol involving integrated concentration, enrichment, and end-point colorimetric detection of foodborne pathogens in large volumes of agricultural water is presented here. Water is filtered through Modified Moore Swabs (MMS), enriched with selective or non-selective media, and detection is performed using paper-based analytical devices (µPAD) imbedded with bacterial-indicative colorimetric substrates.

• Medicine

  
  A Novel in vivo Gene Transfer Technique and in vitro Cell Based Assays for the Study of Bone Loss in Musculoskeletal Disorders Dennis J. Wu¹, Neha Dixit¹, Erika Suzuki¹, Thanh Nguyen², Hyun Seock Shin¹, Jack Davis², Emanual Maverakis³, Iannis E. Adamopoulos^{1,2 1}Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, ²Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children - Northern California, ³Department of Dermatology, University of California, Davis Differentiation of precursor cells into osteoclasts is regulated by cytokines and growth factors. Here, a novel gene transfer technique for differentiation of osteoclasts in vivo and cell culture protocols for differentiating precursor cells into osteoclasts in vitro as a method to study the effects of cytokines on osteoclastogenesis are described.

• Environment

  
  Surface Renewal: An Advanced Micrometeorological Method for Measuring and Processing Field-Scale Energy Flux Density Data Andrew J. McElrone^1,2, Thomas M. Shapland², Arturo Calderon^2,3, Li Fitzmaurice^4,5, Kyaw Tha Paw U⁴, Richard L. Snyder^{4 1}Crops Pathology and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, ²Department of Viticulture & Enology, University of California, Davis, ³Faculty of Agricultural Sciences, University of Chile, ⁴Atmospheric Science, University of California, Davis, ⁵URS Corporation Australia Pty. Ltd. Surface renewal is a micrometeorological method that is being used increasingly to determine energy fluxes, but its technical complexity makes it inaccessible to a broad audience. We describe the steps needed to set up and calibrate a surface renewal field station, to acquire and process data, and to correctly interpret results.

• Neuroscience

  
  Electrophysiological Recording in the Brain of Intact Adult Zebrafish Lindsey Johnston¹, Rebecca E. Ball², Seth Acuff³, John Gaudet⁴, Andrew Sornborger⁵, James D. Lauderdale^{2 1}Department of Genetics, University of Georgia, ²Department of Cellular Biology, University of Georgia, ³College of Engineering, Architecture and Technology, Oklahoma State University, ⁴University of Georgia, ⁵Department of Mathematics, University of California, Davis This paper describes how an adult zebrafish can be immobilized, intubated, and used for in vivo electrophysiological experiments to allow recordings and manipulation of neural activity in an intact animal.

• Bioengineering

  
  Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies Pallavi Daggumati¹, Ozge Kurtulus², Christopher Abbott Reece Chapman³, Damla Dimlioglu¹, Erkin Seker^{1 1}Department of Electrical and Computer Engineering, University of California, Davis, ²Department of Chemical Engineering and Materials Science, University of California, Davis, ³Department of Biomedical Engineering, University of California, Davis We report on techniques to micropattern nanoporous gold thin films via stencil printing and photolithography, as well as methods to culture cells on the microfabricated patterns. In addition, we describe image analysis methods to characterize morphology of the material and the cultured cells using scanning electron and fluorescence microscopy techniques.

• Biology

  
  Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy Chun A. Changou^1,2, Deanna L. Wolfson², Balpreet Singh Ahluwalia^2,3, Richard J. Bold^4,5, Hsing-Jien Kung^5,6, Frank Y.S. Chuang^{1,2,5 1}Department of Biochemistry and Molecular Medicine, University of California, Davis, ²NSF Center for Biophotonics Science & Technology, University of California, Davis, ³University of Tromsø, ⁴Department of Surgery (Division of Surgical Oncology), University of California, Davis, ⁵UC Davis Comprehensive Cancer Center, University of California, Davis, ⁶Department of Biological Chemistry, University of California, Davis Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

• Biology

  
  Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature Andrew J. McElrone^1,2, Brendan Choat³, Dilworth Y. Parkinson⁴, Alastair A. MacDowell⁴, Craig R. Brodersen^{5 1}U.S. Department of Agriculture, ²Department of Viticulture and Enology, University of California - Davis, ³Hawkesbury Institute for the Environment, University of Western Sydney, ⁴Advanced Light Source, Lawrence Berkeley National Lab, ⁵Citrus Research & Education Center, University of Florida High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique that can be used to study the structure and function of plant vasculature in 3D. We demonstrate how HRCT facilitates exploration of xylem networks across a wide range of plant tissues and species.

• Biology

  
  LeafJ: An ImageJ Plugin for Semi-automated Leaf Shape Measurement Julin N. Maloof*¹, Kazunari Nozue*¹, Maxwell R. Mumbach¹, Christine M. Palmer^{1 1}Department of Plant Biology, University of California Davis Demonstration of key methods for high throughput leaf measurements. These methods can be used to accelerate leaf phenotyping when studying many plant mutants or otherwise screening plants by leaf phenotype.

• Bioengineering

  
  On-Chip Endothelial Inflammatory Phenotyping J. Sherrod DeVerse*¹, Keith A. Bailey*¹, Greg A. Foster¹, Vaishali Mittal¹, Stuart M. Altman¹, Scott I. Simon¹, Anthony G. Passerini^{1 1}Department of Biomedical Engineering, University of California, Davis Microfluidic flow chambers etched by photolithography and fabricated from PDMS are applied to probe functional outcomes associated with EC dysfunction and inflammation. In a representative experiment, the ability of differential shear stress to modulate monocytic cell adhesion to cytokine activated EC monolayers is demonstrated.

• Bioengineering

  
  Microfluidic Mixers for Studying Protein Folding Steven A. Waldauer¹, Ling Wu¹, Shuhuai Yao², Olgica Bakajin³, Lisa J. Lapidus^{1 1}Department 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).

• Biology

  
  Fruit Volatile Analysis Using an Electronic Nose Simona Vallone¹, Nathan W. Lloyd², Susan E. Ebeler³, Florence Zakharov^{1 1}Department of Plant Sciences, University of California, Davis, ²Department of Chemical Engineering and Material Science, University of California, Davis, ³Department of Viticulture and Enology, University of California, Davis A rapid method for volatile compound analysis in fruit is described. The volatile compounds present in the headspace of a homogenate of the sample are rapidly separated and detected with ultra-fast gas chromatography (GC) coupled with a surface acoustic wave (SAW) sensor. A procedure for data handling and analysis is also discussed.

• Neuroscience

  
  Inducing Dendritic Growth in Cultured Sympathetic Neurons Atefeh Ghogha¹, Donald A. Bruun¹, Pamela J. Lein^{1 1}Department of Molecular Biosciences, University of California, Davis We describe a protocol for using bone morphogenetic protein-7 (BMP-7) or Matrigel to selectively induce dendritic growth in primary sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rats.

• Bioengineering

  
  Electric Field-controlled Directed Migration of Neural Progenitor Cells in 2D and 3D Environments Xiaoting Meng*¹, Wenfei Li*^2,3, Fraser Young¹, Runchi Gao³, Laura Chalmers³, Min Zhao³, Bing Song^{1 1}School of Dentistry, Cardiff Institute of Tissue Engineering & Repair, Cardiff University, ²Shandong Qianfoshan Hospital, Shandong University School of Medicine, ³Dermatology and Ophthalmology Research, Institute for Regenerative Cures, University of California at Davis This protocol demonstrates methods used to establish 2D and 3D environments in custom-designed electrotactic chambers, which can track cells in vivo/ex vivo using time-lapse recording at the single cell level, in order to investigate galvanotaxis/electrotaxis and other cellular responses to direct current (DC) electric fields (EFs).

• Biology

  
  Quantifying Mixing using Magnetic Resonance Imaging Emilio J. Tozzi¹, Kathryn L. McCarthy¹, Lori A. Bacca², William H. Hartt², Michael J. McCarthy^{1 1}Dept. Food Science and Technology, University of California, Davis, ²Corporate Engineering and Technology Laboratory, Procter & Gamble Company Magnetic resonance imaging (MRI) provides a powerful tool to evaluate the effectiveness of process equipment during operation. We discuss the use of MRI to visualize mixing in a static mixer. The application is relevant to personal care products, but can be applied to a broad range of food, chemical, biomass and biological fluids.

• Bioengineering

  
  Live-cell Imaging of Migrating Cells Expressing Fluorescently-tagged Proteins in a Three-dimensional Matrix Wenting Shih¹, Soichiro Yamada^{1 1}University of California, Davis Cellular processes such as cell migration have traditionally been studied on two-dimensional, stiff plastic surfaces. This report describes a technique for directly visualizing protein localization and analyzing protein dynamics in cells migrating in a more physiologically relevant, three-dimensional matrix.

• Immunology and Infection

  
  Rapid Diagnosis of Avian Influenza Virus in Wild Birds: Use of a Portable rRT-PCR and Freeze-dried Reagents in the Field John Y. Takekawa¹, Nichola J. Hill^1,2, Annie K. Schultz¹, Samuel A. Iverson¹, Carol J. Cardona^3,4, Walter M. Boyce², Joseph P. Dudley^{5 1}USGS Western Ecological Research Center, ²Wildlife Health Center, University of California, Davis, ³Department of Population Health and Reproduction, University of California, Davis, ⁴Department of Veterinary and Biomedical Sciences, University of Minnesota, ⁵Science Applications International Corporation This study describes diagnosis of avian influenza in wild birds using a portable rRT-PCR system. The method takes advantage of freeze-dried reagents to screen wild birds in a non-laboratory setting, typical of an outbreak scenario. Use of molecular tools provides accurate and sensitive alternatives for rapid diagnosis.

• Biology

  
  Transduction of Human Cells with Polymer-complexed Ecotropic Lentivirus for Enhanced Biosafety Bonnie Barrilleaux¹, Paul Knoepfler^{1 1}Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis Lentiviruses are a valuable research tool for exploring gene function; however, researchers may wish to avoid production of pantropic lentivirus encoding known or suspected oncogenes. As an alternative, we present a safer protocol for use of ecotropic lentivirus on human cells modified to express the ecotropic receptor mSlc7a1.

• Bioengineering

  
  Low-Cost Cryo-Light Microscopy Stage Fabrication for Correlated Light/Electron Microscopy David B. Carlson¹, James E. Evans^{1 1}Department of Molecular and Cellular Biology, University of California Davis We demonstrate the fabrication of a low-cost cryogenic stage designed to fit most reflected light microscopes. This lab-built cryogenic stage enables efficient and reliable correlative imaging between cryo-light and cryo-electron microscopy.

• Neuroscience

  
  Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo Benjamin Sadrian¹, Huaiyang Chen¹, Qizhi Gong^{1 1}Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis We present a lentiviral technique for genetic manipulation and visualization of single olfactory sensory neuron axon and its terminal arborization in vivo.

• Bioengineering

  
  Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy Zachary J. Smith*¹, Florian Knorr*¹, Cynthia V. Pagba¹, Sebastian Wachsmann-Hogiu^{1,2 1}Center for Biophotonics Science and Technology, University of California, Davis, ²Department of Pathology and Laboratory Medicine, University of California, Davis We discuss the construction and operation of a complex nonlinear optical system that uses ultrafast all-optical switching to isolate Raman from fluorescence signals. Using this system we are able to successfully separate Raman and fluorescence signals utilizing pulse energies and average powers that remain biologically safe.

• Neuroscience

  
  Electrophysiological Measurements from a Moth Olfactory System Zainulabeuddin Syed¹, Walter S. Leal^{1 1}Department of Entomology, University of California, Davis Insect olfactory systems provide unique opportunities for recording odorant-induced responses in the forms of electroantennograms (EAG) and single sensillum recordings (SSR), which are summed responses from all odorant receptor neurons (ORNs) located on the antenna and from those housed in individual sensilla, respectively.

• Biology

  
  DNA Microarrays: Sample Quality Control, Array Hybridization and Scanning Elva Diaz¹, Gustavo A. Barisone^{1 1}Department of Pharmacology, University of California, Davis We demonstrate the use of DNA microarrays for expression profiling of the nervous system. We describe RNA quality control, sample labeling, and array hybridization and scanning.

• Bioengineering

  
  Measurement of Bioelectric Current with a Vibrating Probe Brian Reid¹, Min Zhao^{1 1}Dermatology, University of California, Davis The manufacture, calibration and use of non-invasive vibrating probes to measure bioelectric current in various biological systems is described.

• Immunology and Infection

  
  Transfection and Mutagenesis of Target Genes in Mosquito Cells by Locked Nucleic Acid-modified Oligonucleotides Nazzy Pakpour¹, Kong Wai Cheung¹, Lattha Souvannaseng¹, Jean-Paul Concordet², Shirley Luckhart^{1 1}Department of Medical Microbiology and Immunology, University of California, Davis, ²Département Génétique et Développement, Institut Cochin, Université Paris Descartes Oligonucleotides can be used to site specifically substitute a single nucleotide of transfected target genes in both Anopheles gambiae and Anopheles stephensi cells.

• Biology

  
  Whole-Cell Recording of Calcium Release-Activated Calcium (CRAC) Currents in Human T Lymphocytes Pratima Thakur¹, Alla F. Fomina^{1 1}Department of Physiology and Membrance Biology, University of California, Davis We provide a step-by-step protocol for whole-cell patch clamp recording of Calcium Release-Activated Calcium (CRAC) currents in peripheral blood mononuclear cell-derived human T lymphocytes.

• Biology

  
  Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS) Tyler J. Weeks¹, Thomas R. Huser^{1,2 1}Center for Biophotonics, University of California, Davis, ²Department of Internal Medicine, University of California, Davis A combination of three single wavelength short-pulsed lasers is used to generate coherent anti-Stokes Raman scattering (CARS) and doubly-resonant CARS (DR-CARS). The difference between these signals provides enhanced sensitivity for otherwise difficult to detect coherent Raman signals, enabling imaging of weak Raman scatterers.

• Immunology and Infection

  
  Visualizing Cell-to-cell Transfer of HIV using Fluorescent Clones of HIV and Live Confocal Microscopy Benjamin Dale¹, Gregory P. McNerney², Deanna L. Thompson², Wolfgang Hübner³, Thomas Huser², Benjamin K. Chen^{1 1}Division of Infectious Diseases, Department of Medicine, Immunology Institute, Mount Sinai School of Medicine, ²NSF Center for Biophotonics, University of California, Davis, ³Structural and Computational Biology Unit, European Molecular Biology Laboratory This visualized experiment is a guide for utilizing a fluorescent molecular clone of HIV for live confocal imaging experiments.

• Neuroscience

  
  Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila Joanna C. Chiu^1,2, Kwang Huei Low^1,3, Douglas H. Pike¹, Evrim Yildirim^1,3, Isaac Edery^{1,3 1}Center for Advanced Biotechnology and Medicine, Rutgers University, ²Current Address: Department of Entomology, College of Agricultural and Environmental Sciences, University of California, Davis, ³Department of Molecular Biology and Biochemistry, Rutgers University We describe procedures for recording daily locomotor activity rhythms of Drosophila and subsequent data analysis. Locomotor activity rhythms are a reliable behavioral output of animal circadian clocks and are used as the standard readout of clock function when studying circadian mutants or examining how the environment regulates the circadian system.

• Biology

  
  Differentiation of Embryonic Stem Cells into Oligodendrocyte Precursors Peng Jiang¹, Vimal Selvaraj¹, Wenbin Deng^{1 1}Department of Cell Biology and Human Anatomy Institute for Pediatric Regenerative Medicine, School of Medicine, University of California, Davis We describe a small molecule-based protocol for differentiation of mouse embryonic stem cells into oligodendrocyte precursor cells (OPCs). This protocol generates Olig2+NG2+ OPCs with high efficiency by 30 days of differentiation. We also describe a method to generate "spiking" OPCs that can fire action potentials.

• Neuroscience

  
  Mouse Models of Periventricular Leukomalacia Yan Shen¹, Jennifer M. Plane¹, Wenbin Deng^{1 1}Department of Cell Biology and Human Anatomy Institute for Pediatric Regenerative Medicine School of, University of California, Davis We established mouse models of periventricular leukomalacia (PVL), the predominant brain injury in premature infants characterized by periventricular white matter lesions. Hypoxia/ischemia with/without systemic infection are the primary causes of PVL. Unilateral carotid ligation and hypoxia exposure with/without lipopolysaccharide injection creates PVL-like lesions in P6 mice.

• Biology

  
  Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo Ingrid Brust-Mascher¹, Jonathan M. Scholey^{1 1}Department of Molecular and Cellular Biology, University of California, Davis This protocol describes the use of microinjection and high resolution imaging in the Drosophila melanogaster syncytial embryo to study mitosis.

• Biology

  
  A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization Bruce W. Draper¹, Cecilia B. Moens^{2 1}Molecular and Cellular Biology, University of California, Davis, ²Division of Basic Science, Fred Hutchinson Cancer Research Center - FHCRC This is a high-throughput sperm cryopreservation protocol for zebrafish. Sperm cryopreserved using this protocol has an average of 25% fertility in subsequent vitro fertilization and is stable over many years.

• Biology

  
  Blood Collection from the American Horseshoe Crab, Limulus Polyphemus Peter Armstrong^1,2, Mara Conrad^{3 1}Department of Molecular and Cell Biology, University of California, Davis, ²Marine Biological Laboratory - MBL- woods hole, ³Department of Biological Sciences, Hunter College of CUNY The American horseshoe crab, Limulus polyphemus, is arguably the most convenient source for large quantities of blood of any invertebrate. The blood is simple in composition, with only one cell-type in the general circulation, the granular amebocyte, and only three abundant proteins in the plasma, hemocyanin, the C-reactive proteins, and α2-macroglobulin. Blood is collected from the heart and the blood cells and plasma are separated by centrifugation.

• Biology

  
  Preparation of Gene Gun Bullets and Biolistic Transfection of Neurons in Slice Culture Georgia Woods¹, Karen Zito^{1 1}Center for Neuroscience, University of California, Davis We describe a method for preparing DNA coated gold bullets and demonstrate the use of such bullets to biolistically transfect neurons in cultured hippocampal slices.

• Biology

  
  Patterning Cells on Optically Transparent Indium Tin Oxide Electrodes Sunny Shah¹, Alexander Revzin^{1 1}Department of Biomedical Engineering, University of California, Davis Non-fouling PEG silane monolayer was desorbed from individually addressable ITO electrodes on glass by application of a reductive potential. Electrochemical stripping of PEG-silane layer from ITO microelectrodes allowed for cell adhesion to take place in a spatially defined fashion, with cellular patterns corresponding closely to electrode patterns.