Here we describe a set of DNA mutation assays that can be combined with the yeast chronological life span model to study the genes/pathways that regulate or contribute to genomic DNA instability during aging.
Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae
1Irell & Manella Graduate School of Biological Sciences, 2Department of Molecular and Cellular Biology, City of Hope Comprehensive Cancer Center and Beckman Research Institute, 3Department of Biochemistry and Molecular Biology, University of Southern California, Norris Comprehensive Cancer Center
The HO-stimulated translocation assay monitors single-strand annealing following the creation of DNA double-strand breaks at multiple loci in diploid Saccharomyces cerevisiae. This mechanism may model genome rearrangements in somatic cells of higher eukaryotes following exposure to high doses of ionizing radiation.
DT40, a model vertebrate genetic system, provides a powerful tool to analyze protein function. Here we describe a simple method that allows qualitative analysis of parameters that influence DNA synthesis during the S-phase in DT40 cells at the single molecule level.
1Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, 2Southern Arizona Veterans Affairs Health Care System, Tucson, AZ, 3Department of Surgery, College of Medicine, University of Arizona, Tucson, 4Biomedical Diagnostics and Research, Tucson, AZ, 5Department of Medicine, College of Medicine, University of Arizona, Tucson
Reduced/absent expression of Pms2 and/or ERCC1 in entire crypts is a frequent event within 10 cm on each side of colonic adenocarcinomas, likely the basis of a field defect with high mutability and progression to cancer. Deficiency in Ku86 or CcOI is much less frequent in these field defects.
Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos
The kinetochore is where the SAC initiates its signal monitoring the mitotic segregation of the sister chromatids. A method is described to visualize the recruitment and turnover of one of the kinetochore proteins and its coordination with the chromosome motion in Drosophila embryos using a Leica laser scanning confocal system.
A quantitative method for the analysis of chromosome replication timing is described. The method utilizes BrdU incorporation in combination with fluorescent in situ hybridization (FISH) to assess replication timing of mammalian chromosomes. This technique allows for the direct comparison of rearranged and un-rearranged chromosomes within the same cell.
1Department of Radiation Oncology, Virginia Commonwealth University, 2Department of Biochemistry & Molecular Biology, Virginia Commonwealth University, 3Department of Anatomy & Neurobiology, Virginia Commonwealth University, 4Massey Cancer Center, Virginia Commonwealth University
This protocol describes a method for visualizing a DNA double-strand break signaling protein activated in response to DNA damage as well as its localization during mitosis.
Xenopus egg extract is a useful model system to investigate the DNA damage checkpoint. This protocol is for the preparation of Xenopus egg extracts and DNA damage checkpoint inducing reagents. These techniques are adaptable to a variety of DNA damaging approaches in the study of the DNA damage checkpoint signaling.
1Institute of Pathology, Laboratory of Molecular Tumor Pathology, Charité - Universitätsmedizin Berlin, 2Institute for Chemistry and Biochemistry, Free University Berlin, 3Laboratory for Functional Genomics Charité (LFGC), Charité - Universitätsmedizin Berlin, 4Comprehensive Cancer Center Charité, Charité - Universitätsmedizin Berlin
This article describes the preparation of freshly obtained melanoma tissue into primary cell cultures, and how to remove contaminations of erythrocytes and fibroblasts from the tumor cells. Finally, we describe how CD133+ putative melanoma stem cells are sorted from the CD133- bulk using Magnetic Activated Cell Sorting (MACS).
Genetic studies in yeast can be employed to investigate the molecular and cellular functions of human genes in cellular DNA metabolism. Methods are described for the genetic characterization of the human WRN gene product defective in the premature aging disorder Werner syndrome in functionally conserved pathways using yeast as a tractable model system.
Growing some flax varieties under nutrient stress results in genomic variation within a subset of the genome and phenotypic variation. A complex insertion at a specific site is associated with growth under various nutrient regimes and with changes in gene expression around this site.
Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization
1Department of Pathology, New York University School of Medicine, 2New York University Center for Health Informatics and Bioinformatics, 3NYU Cancer Institute, 4Department of Pathology and Yale Cancer Center, Yale University School of Medicine
Here we describe a protocol for simultaneous detection of histone modifications by immunofluorescence and DNA sequences by DNA FISH followed by 3D microscopy and analyses (3D immuno-DNA FISH).
The Logic, Experimental Steps, and Potential of Heterologous Natural Product Biosynthesis Featuring the Complex Antibiotic Erythromycin A Produced Through E. coli
The heterologous biosynthesis of erythromycin A through E. coli includes the following experimental steps: 1) genetic transfer; 2) heterologous reconstitution; and 3) product analysis. Each step will be explained in the context of the motivation, potential, and challenges in producing therapeutic natural products using E. coli as a surrogate host.
A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation
1Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Emory University School of Medicine and Children's Health Care of Atlanta, 2Division of Rheumatology, Department of Pediatrics, Emory University School of Medicine and Children's Health Care of Atlanta
We are describing a new method of isolating genomic DNA from whole blood collected for plasma/serology. After plasma collection, the compacted blood is usually discarded. Our novel method represents a significant improvement over existing methods and makes DNA and plasma available from a single collection, without requesting additional blood.
Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease
Spectral Karyotyping (SKY) is an advanced cytogenetics technique to identify genomic and chromosomal aberrations. This technique takes advantage of chromosome painting probes, which allow classification of all chromosomes. SKY can also identify complex chromosome aberrations and segregation defects in mice and humans with various diseases, including polycystic kidney disease.
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.
Micro 3D Printing Using a Digital Projector and its Application in the Study of Soft Materials Mechanics
We demonstrate controlled pattern transformation of swelling gel tubes by elastic instability. A simple projection micro stereo-lithography setup is built using an off-the-shelf digital data projector to fabricate three-dimensional polymeric structures in a layer-by-layer fashion. Swelling hydrogel tubes under mechanical constraint display various circumferential buckling modes depending on dimension.
We use a closed-loop fly-machine interface to investigate general principles in neuronal control.
Gene microarrays are powerful tools in gene expression profiling at a genome-wide level. This technology has application in a variety of biological disciplines including developmental biology and toxicology. In this video, we detail a protocol for global gene expression analysis using a comprehensive oligonucleotide microarray platform for the zebrafish.
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.
MamA is a unique Magnetosome associated protein which was shown to be involved in magnetosome activation. Here we present the purification protocol of MamA deletion mutant (MamAΔ41) from M. magneticum AMB-1.
Described is a two-step labeling process using β-glucosyltransferase (β-GT) to transfer an azide-glucose to 5-hmC, followed by click chemistry to transfer a biotin linker for easy and density-independent enrichment. This efficient and specific labeling method enables enrichment of 5-hmC with extremely low background and high-throughput epigenomic mapping via next-generation sequencing.
We present a public computational web site for the analysis of genomic sequences. It detects DNA sequence patterns with various non-random nucleotide compositions. This resource also generates randomized sequences with diverse levels of complexity.
Construction of a fosmid library with environmental genomic DNA isolated from the vertical depth continuum of a seasonally hypoxic fjord is described. The resulting clone library is picked into 384-well plates and archived for downstream sequencing and functional screening by the application of an automated colony picking system.
Genetic associations often remain unexplained at a functional level. This method aims to assess the effect of phenotype-associated genetic markers on gene expression by analyzing cells heterozygous for transcribed SNPs. The technology allows accurate measurement by MALDI-TOF mass spectrometry to quantify allele-specific primer extension products.
Laser Capture Microdissection of Enriched Populations of Neurons or Single Neurons for Gene Expression Analysis After Traumatic Brain Injury
We describe how to use laser capture microdissection (LCM) to obtain enriched populations of hippocampal neurons or single neurons from frozen sections of the injured rat brain for subsequent gene expression analysis using quantitative real time PCR and/or whole-genome microarrays.
A methodology to isolate high molecular weight and high quality genomic DNA from soil microbial community is described.
TransFLP — A Method to Genetically Modify Vibrio cholerae Based on Natural Transformation and FLP-recombination
A quick method to modify the genome of V. cholerae is described. These modifications include the deletion of single genes, gene clusters and genomic islands as well as the integration of short sequences (e.g. promoter elements or affinity-tag sequences). The method is based on the natural transformation and FLP-recombination.
Karyotyping is a simple and useful technique widely used for detecting genetic alterations. Here we describe a step by step protocol for chromosome spread preparation of human embryonic stem cells for monitoring the chromosomal status of these cells maintained in culture.
The CompoZr Custom Zinc-Finger Nuclease (ZFN) Service enables precise genome editing in any organism or cell line at any locus defined by the user. This article describes the process for the design, manufacture, validation and implementation of the CompoZr Custom ZFN Service.
Creating Rigidly Stabilized Fractures for Assessing Intramembranous Ossification, Distraction Osteogenesis, or Healing of Critical Sized Defects
This article describes a method for stabilizing long bone fractures that is based on the application of modified Ilizarov external fixators 1-3. After application of the fixators and creation of the bone injury, healing can be assessed, distraction osteogenesis can be performed, or non-union or critical sized defect can be created and used to study therapeutic interventions.
Fluorescence-microscopy Screening and Next-generation Sequencing: Useful Tools for the Identification of Genes Involved in Organelle Integrity
A fundamental quest in cell biology is to define the mechanisms that underlie the identity of the organelles that make eukaryotic cells. Here we propose a method to identify the genes responsible for the morphological and functional integrity of plant organelles using fluorescence microscopy and next-generation sequencing tools.
An accurate, short, sophisticated and cheap method is described that assesses telomere length in multiple tissues and species using qRT-PCR. In addition, we will describe a simple assay to assess telomerase activity as a complementary backbone test for telomere length.
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
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.
1Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, 2Department of Microbiology and Immunology, McGill University, 3Department of Medicine, Division of Experimental Medicine, McGill University
A fluorescence in situ hybridization (FISH) method was developed to visually detect viral genomic RNA using fluorescence microscopy. A probe is made with specificity to the viral RNA that can then be identified using a combination of hybridization and immunofluorescence techniques. This technique offers the advantage of identifying the localization of the viral RNA or DNA at steady-state, providing information on the control of intracellular virus trafficking events.
Concentration Determination of Nucleic Acids and Proteins Using the Micro-volume Bio-spec Nano Spectrophotometer
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.
An efficient genome-wide single gene mutation method has been established using Streptococcus sanguinis as a model organism. This method has achieved via high throughput recombinant PCRs and transformations.
This video is a technical demonstration of the hybridization protocol for whole genome tiling path array CGH, which scans the entire human genome using only 25-100 ng of DNA that can be isolated from a variety of sources, including archival formalin fixed material.
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.
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.
The gold standard for DNA methylation analysis is genomic sequencing of bisulphite converted DNA. This method takes advantage of the increased sensitivity of cytosine compared with 5-methylcytosine (5-MeC) to bisulphite deamination under acidic conditions. Unmethylated cytosines can be distinguished from methylated cytosines after PCR amplification of the target genomic DNA.
Many plant tissues, including phloem and xylem from loblolly pine (Pinus taeda L.), contain high levels of phenolics and polysaccharides that interfere with RNA purification. This presentation discusses techniques for the harvest of field-grown tissues and isolation of RNA of sufficient quality for microarrays and other genomic analyses.
1Department of Biochemistry and Molecular Genetics, University of Illinois Chicago - UIC, 2Research Unit on Biomedical Informatics, Universitat Pompeu Fabra, 3Genome Technology Core, Whitehead Institute for Biomedical Research
Here we are presenting a chromatin immunoprecipitation (ChIP) procedure for genome-wide location analysis of protein isoforms that differ in a histone-binding domain. We are applying it to ChIP-Seq analysis to identify the targets of the KDM5A/JARID1A/RBP2 histone demethylase.
The EpiMark 5-hmC and 5-mC Analysis Kit can be used to analyze and quantitate 5-methylcytosine and 5-hydroxymethylcytosine within a spe cific locus. The kit distinguishes 5-mC from 5-hmC by the addition of glucose to the hydroxyl group of 5-hmC via an enzymatic reaction utilizing β-glucosyltransferase (T4-BGT). When 5-hmC occurs In the context of CCGG, this modification converts a cleavable MspI site to a non-cleavable site.
Here we use a human LentiPlex pooled library and traditional sequencing methods to identify gene targets promoting cell survival. We demonstrate how to set up and deconvolute a LentiPlex screen and validate the results.
The manufacture, calibration and use of non-invasive vibrating probes to measure bioelectric current in various biological systems is described.
1Department of Chemistry, Imperial College London, 2Department of Biochemistry, Protein Chip Research Center, Chungbuk National University, 3Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich
Droplet-based microfluidic platforms are promising candidates for high throughput experimentation since they are able to generate picoliter, self-compartmentalized vessels inexpensively at kHz rates. Through integration with fast, sensitive and high resolution fluorescence spectroscopic methods, the large amounts of information generated within these systems can be efficiently extracted, harnessed and utilized.
Extracting DNA from the Gut Microbes of the Termite (Zootermopsis Angusticollis) and Visualizing Gut Microbes
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.
A PCR-based Genotyping Method to Distinguish Between Wild-type and Ornamental Varieties of Imperata cylindrica
We provide a cost-effective and rapid molecular genotyping protocol that employs variety-specific PCR primers that target DNA sequence differences within the chloroplast trnL-F spacer region to differentiate between varieties of Imperata cylindrica (cogongrass) that cannot be distinguished by morphology alone. These varieties include the federally listed noxious weed, cogongrass and closely-related, wide-spread ornamental variety, I. cylindrica var. koenigii (Japanese blood grass).
RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus
In model organisms, transgenesis can manipulate gene functions while RNAi can knockdown specific mRNA transcripts 1-2. This protocol aims to illustrate the techniques needed to introduce stably transmitted DNA and transient double stranded RNA into the necromenic nematode Pristionchus pacificus for studies in evolutionary, developmental, and behavioral biology.