JoVE General
Electricity-Free, Sequential Nucleic Acid and Protein Isolation
1CUBRC, Inc., 2Department of Microbiology and Immunology, State University of New York at Buffalo, School of Medicine and Biomedical Sciences
A tool and chemistries are described to sequentially isolate nucleic acids followed by proteins from a sample without the need for electricity. The tool consists of a sorbent held within a transfer pipette while the isolation chemistries are based on solid-phase extraction principles. The isolated macromolecules can be analyzed by immuno-based and PCR-based assays.
JoVE General
NanoDrop Microvolume Quantitation of Nucleic Acids
Thermo Scientific NanoDrop Products, Wilmington, Delaware
The use of NanoDrop microvolume systems as practical and efficient alternatives to traditional nucleic acid quantitation methodology is described through the demonstration of two microvolume nucleic acid quantitation protocols.
JoVE Immunology and Infection
Separation of Single-stranded DNA, Double-stranded DNA and RNA from an Environmental Viral Community Using Hydroxyapatite Chromatography
1Department of Microbial and Environmental Genomics, The J. Craig Venter Institute, 2Department of Synthetic Biology and Bioenergy, The J. Craig Venter Institute
We describe an efficient method to separate single-stranded DNA, double-stranded DNA and RNA molecules from environmental viral communities. Nucleic acids are fractionated using hydroxyapatite chromatography with increasing concentrations of phosphate-containing buffers. This method permits the isolation of all viral nucleic acid types from environmental samples.
JoVE General
Analyzing and Building Nucleic Acid Structures with 3DNA
1Department of Chemistry & Chemical Biology and BioMaPS Institute for Quantitative Biology, Rutgers - The State University of New Jersey, 2Department of Biological Sciences, Columbia University
The 3DNA software package is a popular and versatile bioinformatics tool with capabilities to analyze, construct, and visualize three-dimensional nucleic acid structures. This article presents detailed protocols for a subset of new and popular features available in 3DNA, applicable to both individual structures and ensembles of related structures.
JoVE Bioengineering
On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids
Mechanical Engineering, Stanford University
Isotachophoresis (ITP) is a robust electrokinetic separation and preconcentration technique with applications ranging from toxin detection to sample preparation. We review the physical principles of ITP and the methodology of applying this technique to two specific example applications: separation and detection of small molecules and purification of nucleic acids from cell culture lysate.
JoVE General
Primer-Free Aptamer Selection Using A Random DNA Library
1Department of Pathology, Hershey Medical Center, Pennsylvania State University, 2Department of Chemistry, Pennsylvania State University, 3Departments of Pathology, and Biochemistry and Molecular Biology, Hershey Medical Center, Pennsylvania State University, 4Materials Research Institute, Pennsylvania State University
SELEX protocols comprise multiple rounds of selection, each of which require regeneration of bound ligands, which in turn require fixed primer sequences flanking the random library regions. These fixed primer sequences can interfere with the selection process (false positives and negatives). Here we present a primer-free protocol.
JoVE Immunology and Infection
Using a Pan-Viral Microarray Assay (Virochip) to Screen Clinical Samples for Viral Pathogens
1Department of Laboratory Medicine, University of California, San Francisco, 2Division of Infectious Diseases, University of California, San Francisco
The Virochip is a pan-viral microarray designed to simultaneously detect all known viruses as well as novel viruses on the basis of conserved sequence homology. Here we demonstrate how to run a Virochip assay to analyze clinical samples for the presence of both known and unknown viruses.
JoVE Immunology and Infection
Transfection and Mutagenesis of Target Genes in Mosquito Cells by Locked Nucleic Acid-modified Oligonucleotides
1Department 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.
JoVE General
Polymerase Chain Reaction: Basic Protocol Plus Troubleshooting and Optimization Strategies
Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles
PCR has emerged as a common technique in many molecular biology laboratories. Provided here is a quick guide to several conventional PCR protocols. Because each reaction is a unique experiment, optimal conditions required to generate a product vary. Understanding the variables in a reaction will greatly enhance troubleshooting efficiency, thereby increasing the chance to obtain the desired result.
JoVE Bioengineering
Microfluidic Chip Fabrication and Method to Detect Influenza
1Department of Mechanical Engineering, Boston University, 2Department of Biomedical Engineering, Boston University
An integrated microfluidic thermoplastic chip has been developed for use as a molecular diagnostic. The chip performs nucleic acid extraction, reverse transcriptase, and PCR. Methods for fabricating and running the chip are described.
JoVE Chemistry
Rapid Colorimetric Assays to Qualitatively Distinguish RNA and DNA in Biomolecular Samples
Department of Chemistry, University of Virginia
A suite of colorimetric assays is described for rapidly distinguishing protein, RNA, DNA, and reducing sugars in potentially heterogeneous biomolecular samples.
JoVE Immunology and Infection
Locked Nucleic Acid Flow Cytometry-fluorescence in situ Hybridization (LNA flow-FISH): a Method for Bacterial Small RNA Detection
Center for Bio/Molecular Science and Engineering, Naval Research Laboratory
A novel high-throughput method is described that enables the detection and relative quantitation of small RNA and mRNA expression from single bacterial cells using locked nucleic acid probes and flow cytometry-fluorescence in situ hybridization.
JoVE General
Concentration Determination of Nucleic Acids and Proteins Using the Micro-volume Bio-spec Nano Spectrophotometer
Shimadzu, Scientific Instruments
This communication presents data on the accuracy and reproducibility of the BioSpec-nano UV-VIS spectrophotometer for dsDNA and protein quantitation. Even with ultra-small volumes (1 to 2 L), reproducibility is excellent, while the automated wiping function improves throughput and results in minimal carryover for more precise results.
JoVE General
Extracting DNA from the Gut Microbes of the Termite (Zootermopsis Angusticollis) and Visualizing Gut Microbes
Department of Environmental Science and Engineering, California Institute of Technology - Caltech
This video illustrates the technique for extracting DNA from the species of microbes resident in the termite hindgut. The preparation of a wet mount slide, which is useful for visualizing the gut microbial community is also illustrated, and a tour through the species-rich gut environment is given.
JoVE General
DNA Extraction from Paraffin Embedded Material for Genetic and Epigenetic Analyses
1Department of Integrative Oncology, BC Cancer Research Centre, 2Interdisciplinary Oncology Program, University of British Columbia - UBC, 3Photography/Video Production, Multi-Media Services, BC Cancer Agency, 4Department of Pathology and Laboratory Medicine, University of British Columbia - UBC
This video demonstrates the protocol for DNA extraction from formalin-fixed paraffin-embedded material. This is a multi-day procedure in which tissue sections are deparaffinized with xylene, rehydrated with ethanol and treated with proteinase K to purify and isolate DNA for subsequent gene-specific or genome-wide analysis.
JoVE Bioengineering
Bacterial Detection & Identification Using Electrochemical Sensors
1Research Service, Veterans Affairs Greater Los Angeles Healthcare System, 2Department of Urology, The David Geffen School of Medicine, University of California, Los Angeles, 3GeneFluidics, 4Division of Infectious Diseases, Veterans Affairs Greater Los Angeles Healthcare System, 5Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles
We describe an electrochemical sensor assay method for rapid bacterial detection and identification. The assay involves a sensor array functionalized with DNA oligonucleotide capture probes for ribosomal RNA (rRNA) species-specific sequences. Sandwich hybridization of target rRNA with the capture probe and a horseradish peroxidase-linked DNA oligonucleotide detector probe produces a measurable amperometric current.
JoVE General
The ITS2 Database
1Department of Bioinformatics, Biocenter, University of Würzburg, 2Institute of Pharmacy and Food Chemistry, University of Würzburg
The ITS2 Database is a workbench for phylogenetic inference simultaneously considering sequence and secondary structure of the internal transcribed spacer 2. This includes data collection with accurate annotation, structure prediction, multiple sequence-structure alignment and fast tree calculation. In a nutshell, this workbench simplifies first phylogenetic analyses to a few clicks.
JoVE Bioengineering
High efficiency, Site-specific Transfection of Adherent Cells with siRNA Using Microelectrode Arrays (MEA)
School of Biological and Health Systems Engineering, Arizona State University
The article details the protocol for site-specific transfection of scrambled sequence of siRNA in an adherent mammalian cell culture using a microelectrode array (MEA).
JoVE General
DNA Stable-Isotope Probing (DNA-SIP)
Department of Biology, University of Waterloo
DNA stable-isotope probing is a cultivation-independent method to identify and characterize active communities of microorganisms that are capable of utilizing specific substrates. Assimilation of substrate enriched in heavy isotope leads to incorporation of labelled atoms into microbial biomass. Density gradient ultracentrifugation retrieves labelled DNA for downstream molecular analyses.
JoVE General
Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
Department of Biochemistry, University of Toronto
Here we describe an assay that employs the power of microinjection coupled with fluorescent in situ hybridization in order to accurately measure the nuclear export kinetics of mRNA in mammalian somatic cells.
JoVE Immunology and Infection
Detection of Bacteria Using Fluorogenic DNAzymes
1Department of Biochemistry and Biomedical Sciences, McMaster University, 2Department of Chemistry and Chemical Biology, McMaster University
We have recently reported a novel approach for generating fluorogenic DNAzyme probes that can be applied to set up a simple, "mix-and-read" fluorescent assay for bacterial detection. These special DNA probes catalyze the cleavage of a chromophore-modified DNA-RNA chimeric substrate in the presence of crude extracellular mixture (CEM) produced by a specific bacterium, thereby translating bacterial detection into fluorescence signal generation. In this report we will describe key experimental procedures where a specific DNAzyme probe denoted "RFD-EC1" is employed for the detection of the model bacterium, Escherichia coli (E. coli).
JoVE Immunology and Infection
Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses
The study describes a cost-effective method for the identification of the source of fecal/urine contamination or contamination by nitrates in water using qPCR for the specific quantification of human/porcine/bovine DNA viruses, adenoviruses and polyomaviruses, proposed as MST tools.
JoVE General
The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation
Gene Expression Division, Bio-Rad Laboratories, Inc
This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation system.
JoVE General
DNA-based Fish Species Identification Protocol
This publication describes how to use the Agilent Fish Species Identification System to identify the species of a fish by extracting DNA and performing PCR and RFLP analysis.
JoVE Immunology and Infection
In vitro tRNA Methylation Assay with the Entamoeba histolytica DNA and tRNA Methyltransferase Dnmt2 (Ehmeth) Enzyme
1Faculty of Medicine, Rappaport Institute, Technion - Israel Institute of Technology, 2The Pharmacy and Biochemistry Institute, Johannes Gutenberg University
This protocol describes the preparation of a synthetic tRNA substrate for the Entamoeba histolytica DNA/tRNA methyltransferase 2 (Dnmt2) homolog Ehmeth and the measure of its methyltransferase activity. This experimental approach can be used for investigating the activity of other Dnmt2 proteins.
JoVE Immunology and Infection
Development of Cell-type specific anti-HIV gp120 aptamers for siRNA delivery
1Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 2Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 3Shared Resource-DNA/RNA Peptide, Beckman Research Institute of City of Hope
Several 2’-Fluoro RNA aptamers against HIV-1Ba-L gp120 with nanomole affinity are isolated from a RNA library by in vitro SELEX procedure. A new dual inhibitory function anti-gp120 aptamer-siRNA chimera is created and shows considerable promise for systemic anti-HIV therapy.
JoVE General
High-throughput Purification of Affinity-tagged Recombinant Proteins
Department of Life Sciences, Imperial College London
We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format.
JoVE Applied Physics
Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet (VUV) Synchrotron Radiation
Chemical Sciences Division, Lawrence Berkeley National Laboratory
A molecular beam coupled to tunable vacuum ultraviolet photoionization mass spectrometer at a synchrotron provides a convenient tool to explore the electronic structure of isolated gas phase molecules and clusters. Proton transfer mechanisms in DNA base dimers were elucidated with this technique.
JoVE General
Denaturing Urea Polyacrylamide Gel Electrophoresis (Urea PAGE)
1School of Biological Sciences, Nanyang Technological University, Singapore - NTU, 2Singapore-MIT Alliance for Reserach and Technology (SMART)
Denaturing urea polyacrylamide gel electrophoresis is used to separate single-stranded DNA or RNA up to a limit of 500 nucleotides. Urea in combination with heat denatures samples and unstructured single strands migrate within the gel matrix according to their molecular weight.
JoVE General
Optimized PCR-based Detection of Mycoplasma
Product Management, Sigma-Aldrich
The LookOut Mycoplasma PCR Detection Kit utilizes the polymerase chain reaction (PCR), which is established as the method of choice for highest sensitivity in the detection of Mycoplasma, Acholeplasma, and Ureaplasma contamination in cell cultures and other cell culture derived biologicals.
JoVE Immunology and Infection
Sample Preparation of Mycobacterium tuberculosis Extracts for Nuclear Magnetic Resonance Metabolomic Studies
1School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, 2Department of Chemistry, University of Nebraska-Lincoln
The metabolomic profile of Mycobacterium tuberculosis is determined after growth in broth cultures. Conditions can be varied to test the effects of nutritional supplements, oxidants, and anti-tuberculosis agents on the metabolic profile of this microorganism. Procedure for extract preparation is applicable for both 1D 1H and 2D 1H-13C NMR analyses.
JoVE Immunology and Infection
An Introduction to Parasitic Wasps of Drosophila and the Antiparasite Immune Response
1Biology Department, The City College of New York, CUNY, 2The Graduate Center, The City University of New York
Parasitoid (parasitic) wasps constitute a major class of natural enemies of many insects including Drosophila melanogaster. We will introduce the techniques to propagate these parasites in Drosophila spp. and demonstrate how to analyze their effects on immune tissues of Drosophila larvae.
JoVE General
Monitoring Equilibrium Changes in RNA Structure by 'Peroxidative' and 'Oxidative' Hydroxyl Radical Footprinting
1Department of Chemistry, Hunter College, 2Department of Biochemistry, Albert Einstein College of Medicine
This protocol describes how to quantify the Mg(II)-dependent formation of RNA tertiary structure by two methods of hydroxyl radical footprinting.
JoVE Immunology and Infection
Diagnosing Pulmonary Tuberculosis with the Xpert MTB/RIF Test
1Institute for Infectious Diseases, University of Bern, 2MCL Laboratories Inc.
The Xpert MTB/RIF test integrates sample decontamination, hands-free operation, on-board sample processing, and ultra-sensitive hemi-nested PCR for the simultaneous detection of Mycobacterium tuberculosis and rifampicin resistance, either in expectorated sputum or concentrated sputum sediments, in approximately two hours. Testing is standardized and requires only moderate laboratory infrastructure and training.
JoVE General
RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes
1Biology Department, New Mexico State University, 2Molecular Biology Department, New Mexico State University
In this protocol we combine RNAi-mediated gene silencing with an in vivo diuresis assay to study the effects knockdown of genes of interest has on mosquito fluid excretion.
JoVE Bioengineering
Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry
1Biomedical Engineering Department, Johns Hopkins University School of Medicine, 2Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, 3Wilmer Eye Institute, Johns Hopkins University School of Medicine, 4Institute for Nanobiotechnology, Johns Hopkins University School of Medicine
A protocol for nanoparticle tracking analysis (NTA) and high-throughput flow cytometry to evaluate polymeric gene delivery nanoparticles is described. NTA is utilized to characterize the nanoparticle particle size distribution and the plasmid per particle distribution. High-throughput flow cytometry enables quantitative transfection efficacy evaluation for a library of gene delivery biomaterials.
JoVE General
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
School of Biology, Georgia Institute of Technology
This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.
JoVE General
Protein Crystallization for X-ray Crystallography
Molecular Biochemistry and Biophysics, Yale University
The 3-D structure of a molecule provides a unique understanding of how the molecule functions. The principal method for structure determination at near-atomic resolution is X-ray crystallography. Here, we demonstrate the current methods for obtaining three-dimensional crystals of any given macromolecule that are suitable for structure determination by X-ray crystallography.
JoVE Immunology and Infection
Ex Vivo Red Blood Cell Hemolysis Assay for the Evaluation of pH-responsive Endosomolytic Agents for Cytosolic Delivery of Biomacromolecular Drugs
1Department of Biomedical Engineering, Vanderbilt University, 2Vanderbilt Institute for Nanoscale Science & Engineering, Vanderbilt University, 3Interdisciplinary Materials Science Program, Vanderbilt University, 4Monroe Carell Jr. Children's Hospital, Vanderbilt University Medical Center, 5Department of Chemical & Biomolecular Engineering, Vanderbilt University, 6Department of Cancer Biology, Vanderbilt University
A hemolysis assay can be used as a rapid, high-throughput screen of drug delivery systems' cytocompatibility and endosomolytic activity for intracellular cargo delivery. The assay measures the disruption of erythrocyte membranes as a function of environmental pH.
JoVE Immunology and Infection
Isolation of Precursor B-cell Subsets from Umbilical Cord Blood
1Department of Pathology and Anatomical Sciences, University of Missouri-Columbia, 2Laboratory for Infectious Disease Research, University of Missouri-Columbia
Here we describe a protocol for isolating subsets of precursor B-cells from umbilical cord blood. A sufficient quantity and quality of nucleic acids may be extracted from the cells and used in subsequent assays utilizing DNA or RNA.
JoVE Neuroscience
Transcriptome Analysis of Single Cells
1Department of Pharmacology, University of Pennsylvania, 2The Penn Genome Frontiers Institute, University of Pennsylvania
In this article we describe a simple method for the harvesting of single cells from rat primary neuronal cultures and subsequent transcriptome analysis using aRNA amplification. This approach is generalizable to any cell type.
JoVE Application Notes
LookOut Mycoplasma Elimination Kit - ADVERTISEMENT
Product Management, Sigma-Aldrich
The LookOut Mycoplasma elimination kit combines biological agents that reliably and completely eliminate mycoplasma contamination with minimal cytotoxic effect on cells.
JoVE Bioengineering
Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone
1Electrical Engineering Department, University of California, Los Angeles, 2Bioengineering Department, University of California, Los Angeles, 3California NanoSystems Institute (CNSI), University of California, Los Angeles
We review our recent results on the integration of fluorescent microscopy and imaging flow cytometry tools on a cell-phone using compact and cost-effective opto-fluidic attachments. These cell-phone based micro-analysis devices might be useful for cytometric analysis, such as performing various cell counting tasks as well as for high-throughput screening of e.g., water samples in resource limited settings.
JoVE Immunology and Infection
Glass Wool Filters for Concentrating Waterborne Viruses and Agricultural Zoonotic Pathogens
1Wisconsin Water Science Center, United States Geological Survey, 2University of Wisconsin – Madison, 3Agricultural Research Service, United States Department of Agriculture, 4Alaska Science Center, United States Geological Survey
Glass wool filters have been used to concentrate waterborne viruses by a number of research groups around the world. Here we show a simple approach for constructing glass wool filters and demonstrate the filters are also effective in concentrating waterborne viral, bacterial and protozoan pathogens.
JoVE Immunology and Infection
A 1.5 Hour Procedure for Identification of Enterococcus Species Directly from Blood Cultures
1Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Cente, 2Pasadena, CA, Southern California Permanente Medical Group, 3Detroit, Detroit Medical Center, 4Woburn, MA, AdvanDx
A rapid protocol for the direct identification of Enterococcus faecalis and other Enterococcus species from a positive blood culture using a Peptide Nucleic Acid fluorescent in situ hybridization assay (PNA FISH).
JoVE Clinical and Translational Medicine
Detection and Genogrouping of Noroviruses from Children's Stools By Taqman One-step RT-PCR
1Laboratorio de Investigación y Desarrollo (LID), Universidad Peruana Cayetano Heredia, 2Bloomberg School of Public Health, Johns Hopkins University, 3Laboratorio de Diagnostico Molecular, Facultad de Medicina, University of Concepcion,Chile, 4University of California San Diego School of Medicine
A One-Step RT-PCR assay for detection and genogroup identification of Norovirus isolates from children’s stools, that utilizes primers and TaqMan probes specific to the open reading frame 1 (ORF1)-ORF2 junction region, the most conserved region of the Norovirus genome is described. A non-commercial, cost-effective RNA extraction method is detailed.
JoVE Immunology and Infection
RNA Isolation of Pseudomonas aeruginosa Colonizing the Murine Gastrointestinal Tract
1Department of Pediatrics, University of Texas Southwestern Medical Center, 2Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 3Department of Pediatrics and Microbiology, University of Texas Southwestern Medical Center
A reliable method for the RNA isolation of Pseudomonas aeruginosa recovered from murine cecums is described. The RNA recovered is of sufficient quantity and quality for subsequent qPCR, transcription profiling, and RNA Seq experiments. This technique can be adapted for RNA isolation of other intestinal microbes.
JoVE Neuroscience
Optimized Analysis of DNA Methylation and Gene Expression from Small, Anatomically-defined Areas of the Brain
Max Planck Institute of Psychiatry
A streamlined workflow to study DNA methylation and gene expression changes upon early-life stress is shown. Starting from maternal separation of newborn mice and isolation of discrete brain tissues, we represent a protocol to simultaneously isolate DNA and RNA from brain tissue punches for subsequent bisulfite sequencing and RT-PCR analysis.
JoVE Immunology and Infection
Prediction of HIV-1 Coreceptor Usage (Tropism) by Sequence Analysis using a Genotypic Approach
1Institute of Virology, University of Cologne, 2Max Planck Institute for Informatics, 3Institute for Immune genetics, 4Department of Gastroenterology, Hepatology and Infectiology, University of Duesseldorf, 5Department of Dermatology, University of Essen, 6Department of Internal Medicine, University of Cologne, 7Augustinerinnen Hospital
The prediction of the coreceptor usage of HIV-1 is required for the administration of a new class of antiretroviral drugs, i.e. coreceptor antagonists. It can be performed by sequence analysis of the env gene and subsequent interpretation through an internet based interpretation system (geno2pheno[coreceptor]).
JoVE General
Automated System for Single Molecule Fluorescence Measurements of Surface-immobilized Biomolecules
1Physics Department, Boston University, 2Department of Biomedical Engineering, Boston University
In this article we describe how we obtain FRET traces from individual DNA molecules immobilized to a surface using an automated scanning confocal microscope.
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