The most commonly used markers for selection of transgenic Arabidopsis are resistance to the antibiotic kanamycin and to the herbicide glufosinate ammonium. Resistance to kanamycin is conferred by a bacterial gene encoding the enzyme neomycin phosphotransferase (NPT). In this protocol, kanamycin-resistant seedlings are selected on solid medium. - [Read Kanamycin Selection of Transformed Arabidopsis Protocol]
This protocol describes the covalent coupling of antibodies to biotin. Biotin groups bind with extremely high affinity to streptavidin and avidin, both of which are available commercially coupled with enzymes, fluorescent dyes, or iodine. A biotinylated primary antibody, therefore, can be detected with any of a wide variety of different labels. The biotinylation reaction is simple and mild, and rarely inactivates the antibody. - [Read Labeling Antibodies with Biotin Protocol]
Direct labeling of purified antibodies is the method of choice when simultaneously visualizing two or more antibodies of the same species, class, or subclass. This allows the localization of multiple antigens to be compared in the same cell, tissue, or sample. Labeled primary antibodies are also useful for improving background-to-readout ratios, and they can be essential for immunoassays in which good quantification is needed. - [Read Labeling Antibodies with Fluorochromes Protocol]
This protocol describes a simple chemical oxidation method for labeling antibodies with iodine. Iodide-125 (supplied as NaI) is oxidized to form iodine-125 (I2), which attacks tyrosyl and histidyl side chains. The iodinated antibodies are easily detected and quantitated using gamma counters or film. They are used primarily in immunoassays, but other techniques can be adapted conveniently to the iodine detection method. - [Read Labeling Antibodies with Iodine Protocol]
This method for tagging monoclonal antibodies involves growing hybridomas in the presence of radioactive amino acids. This protocol can be particularly useful when conventional labeling techniques cause the antibody to lose activity. The labeled antibodies that result are essentially identical to the unlabeled antibodies. - [Read Labeling Monoclonal Antibodies by Biosynthesis Protocol]
Protocol describes the use of agarose plugs for isolation of yeast artificial chromosome (YAC) DNA. The DNA can then be run on a pulsed-field gel and used for microinjection to produce transgenic mice. - [Read Large-Scale Preparation of Agarose Plugs of Yeast DNA Protocol]
Protocol used chiefly to generate large stocks of double-stranded DNA of strains of M13 that are routinely used as cloning vectors. Large amounts of single-stranded DNA of an individual recombinant may occasionally be needed for specific purposes, e.g., to generate many preparations of a particular radiolabeled probe or to construct large numbers of site-directed mutants. - [Read Large-scale Preparation of Single-stranded and Double-stranded Bacteriophage M13 DNA Protocol]
Two methods are provided for purifying glycoproteins using wheat-germ agglutinin or concanavalin A-Sepharose. Because lectin-affinity matrices can bind a few milligrams of protein per milliliter of affinity matrix, only a small amount of affinity gel matrix is required. The batchwise method is recommended when protein volume is large. - [Read Lectin-Agarose Affinity Chromatography Protocol]
Leukostat Staining of Cytospin Preparations to Detect Apoptosis. Shailaja Kasibhatla et al. Leukostat staining is used to visualize nuclear changes and apoptotic body formation that are characteristic of apoptosis. Cells are viewed under a light microscope and counted to quantify apoptosis. This protocol can be used both for cells that grow in suspension and for adherent cells. - [Read Leukostat Staining of Cytospin Preparations to Detect Apoptosis]
Protocol for ligating plasmid and target DNAs in low-melting-temperature agarose. Ligation in low-melting-temperature agarose is much less efficient than ligation with purified DNA in free solution and requires a large amount of DNA ligase. The method is used chiefly for rapid subcloning of segments of DNA in dephosphorylated vectors and assembling recombinant constructs. - [Read Ligating Plasmid and Target DNAs in Low-melting-temperature Agarose Protocol]
Pilot ligations and packaging reactions are used to establish the amounts of fragmented genomic DNA and bacteriophage {lambda} arms that yield the maximum number of recombinants. Additional ligation and packaging reactions may then be set up to yield a comprehensive library of genomic DNA. - [Read Ligation of Bacteriophage lambda Arms to Fragments of Foreign Genomic DNA Protocol]
Linkage analysis provides information on sugar type, ring size, and substitution positions for each monosaccharide. The method in this protocol, using NaOH as the base, is one of the simpler linkage analysis methods. It requires approximately 1-5 µg of carbohydrate. - [Read Linkage Analysis Using the NaOH Methylation Method Protocol]
Lipoplex (cationic liposome-DNA complex) is formed via electrostatic interaction of anionic nucleic acids with cationic liposomes. A thin film of lipids is dried on the bottom of a glass tube and rehydrated in an aqueous solution. The resulting liposome suspension is passed through polycarbonate filters of desired pore size. This protocol also describes the preparation, physical properties, and biological activity of liposome-polycation-DNA (LPD) nanoparticles. - [Read Lipoplex and LPD Nanoparticles for In Vivo Gene Delivery Protocol]
To image early cleavages and chromatin dynamics, it is convenient to use histone H2B fused to GFP or lamin::GFP. Time-lapse movies can be obtained using conventional confocal microscope systems and their included software. Early embryos dissected from transgenic hermaphrodites are placed with egg salts on agar pads. - [Read Live Imaging of Caenorhabditis elegans: Examples]
Caenorhabditis elegans, a small (adults are ~1 mm long), free-living soil nematode that feeds on bacteria, is an ideal organism for applying various live microscopy techniques. This protocol describes useful techniques for preparing C. elegans for live microscopic analysis. Details of sample preparation depend on the developmental stage of the worm to be studied. - [Read Live Imaging of Caenorhabditis elegans: Preparation of Samples]
GFP serves as a molecular marker that can be imaged dynamically in living cells, both in its native form & as a fusion to other proteins. For GFP imaging, plants present the challenge of autofluorescence from chlorophyll, lignified cell walls, vacuolar contents, and other cell materials, all of which can obscure the GFP signal. Maximizing the signal-to-noise ratio is a major concern, and careful consideration should be given to the choice of tissue imaged, GFP expression level, etc. - [Read Live-Cell Imaging of GFP in Plants]
Protocol illustrates the rules of successful long PCR: No more than 1 ng of template DNA is used per microliter of PCR in a 100-µl reaction; approximately 0.1 µl of KlentaqLA (not plain Taq) is used per kilobase of target (for targets >10 kb, 1-1.3 µl of enzyme should be used); the Mg++ concentration is considered as the excess over the level of dNTPs. - [Read Long and Accurate PCR Protocol]
Long PCR Protocol- http://www.cshprotocols.org/cgi/content/extract/2006/2/pdb.prot3841
Protocol can be used to amplify DNA up to 25 kb in length. To reduce the chance of contamination with exogenous DNAs, prepare and use a special set of reagents and solutions for PCR only. Bake all glassware for 6 hours at 150°C and autoclave all plasticware. - [Read Long PCR Protocol]
In Vitro Translated Xenopus Mos Kinase Assay Protocol. In response to progesterone, immature Xenopus oocytes mature to eggs that can be fertilized. The Mos protein kinase is essential for oocyte maturation, most likely due to its ability to activate the MAP kinase cascade. This MAP kinase cascade eventually leads to the activation of Cdc2/cyclin B and entry into M phase. In this protocol, tagged Mos kinase is translated in vitro, immunopurified, and used in a kinase assay.