desired Protocols

Category: Immunology: Immunoprecipitation Protocols: Chromatin Immunoprecipitation Protocols

Genome-wide location analysis, also known as ChIP-Chip, combines chromatin immunoprecipitation and DNA microarray analysis to identify protein-DNA interactions that occur in living cells. Protein-DNA interactions are captured in vivo by chemical crosslinking. Cell lysis, DNA fragmentation and immunoaffinity purification of the desired protein will co-purify DNA fragments that are associated with that protein. - [Read Chromatin Immunoprecipitation and Microarray-Based Analysis of Protein Location Protocol]

Category: DNA Protocols: cDNA Library Protocols: cDNA Library Construction Protocols

Protocol for cloning genes from a phage library. Includes: Titer and plate out phage; Lift plaques onto filters and prepare them for screening; Make a probe; Hybridize the probe to the filters; Wash the filters and expose to film; Purify putative plaques; Excise plasmid from the desired phage. - [Read Clone Genes From a Phage Library Protocol]

Category: Viral Manipulation Protocols: Phage Protocols

Using hybridization, it is possible to identify a single recombinant that carries the desired target sequence on a filter that carries the imprint of 15,000 or more plaques. - [Read Hybridization of Bacteriophage DNA on Filters Protocol]

Category: Cloning Protocols: Mutagenesis Protocols

Protocol for in vitro mutagenesis using double-stranded DNA templates. Two oligonucleotides are used to prime DNA synthesis catalyzed by a high-fidelity thermostable polymerase on a denatured plasmid template. The two oligonucleotides both contain the desired mutation and occupy the same starting and ending positions on opposite strands of the plasmid DNA. - [Read In Vitro Mutagenesis Using Double-stranded DNA Templates: Selection of Mutants with DpnI]

Category: Primary Cell Isolation and Culture Protocols: Laser Capture Microdissection Protocols

LCM utilizes an infrared laser integrated into a standard microscope. A transparent cap is attached to a thermoplastic transparent membrane which lies directly on the surface of a routinely prepared tissue section on a glass slide. The investigator examines the tissue section microscopically and activates the laser when the desired cells underlie the target. This in turn activates the membrane with subsequent binding and procurement of the cells of interest. - [Read Laser Capture Microdissection (LCM)]

Category: Gene Delivery Protocols: DNA Nanoparticles Protocols

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]

Category: PCR Protocols

PCR can be used to identify rare DNA sequences in DNA libraries by increasing the abundance of a particular sequence.  This is accomplished by subdividing the original library into pools of decreased complexity and screening each pool or group of pools for a given DNA sequence.  A pool that contains the desired clone is subsequently subdivided into smaller pools, each of which is screened using the same PCR protocol that was used for the primary screen. - [Read PCR-Based Screening of DNA Libraries Protocol]

Category: Gene Delivery Protocols: DNA Nanoparticles Protocols

This protocol describes the preparation of polyethylenimine (PEI)/DNA nanoparticles for targeted gene delivery. This delivery strategy improves the efficiency of gene transfer by enhancing the entry of gene vectors into the desired cells and reducing uptake by nontarget cells. We describe here methods for the conjugation of targeting peptides to PEIs, formation of DNA complexes using the conjugated PEIs or nonconjugated PEIs together with targeting peptides, and cell transfection. - [Read PEI Nanoparticles for Targeted Gene Delivery Protocol]

Category: Microscopy Protocols: Live-Cell Imaging Protocols

This protocol describes a method for observing and measuring the movement of RNA molecules in the nucleus of living mammalian cells. Caged fluorescein-labeled DNA oligonucleotides are introduced into living mammalian cells, where they demonstrably hybridize to complementary RNA. After site-specific photoactivation at desired sites within the cell, the RNA movements away from those sites are followed and digitally recorded using a rapid acquisition microscopy system. - [Read Photoactivation-Based Labeling and In Vivo Tracking of RNA Molecules in the Nucleus]

Category: Microinjection Protocols: Microinjection of Proteins Protocols

his protocol provides methods for the preparation of protein samples and for loading them into pulled microinjection pipettes. Stock solutions of proteins are thawed, diluted (if desired), centrifuged at high speed to remove aggregates, and kept on ice until loading. Loading into micropipettes can be done using either a "front-loading" or a "backfilling" procedure. - [Read Preparation and Loading of Protein Samples for Microinjection Protocol]

Category: Chromatography Protocols: Ion Exchange Chromatography Protocols

Protocol for the preparation of ion-exchange chromatography column.  Ion-exchange chromatography (IEC) can be used as a crude step in a protein purification scheme, or, with proper preparation, as a high-resolution step.  If high resolution is desired, considerable care should be taken during column preparation, choice of IEC media, and column packing. - [Read Preparation of an Ion-Exchange Column Protocol]

Category: Protein Protocols: Western Blot Protocol

Western blotting using enriched membrane preparation and postsynaptic densities are desired. (BD Biosciences) - [Read Preparation of Brain Membrane Fractions for Western Blot Analysis]

Category: RNAi Technology Protocols: RNAi Mouse Embryos and Oocytes Protocols

Protocol describes in vitro transcription with the SP6 polymerase.  For other polymerases (T3, T7), simply use the appropriate buffer and desired RNA polymerase instead of the SP6 polymerase. - [Read Preparation of dsRNA Molecules for RNAi in Mouse Oocytes and Early Embryos Protocol]

Category: Immunology: Mononuclear Cell Isolation Protocols: T-Cell Isolation Protocols

Protocols utilize T hybridomas to detect expression of peptide-MHC complexes, since these cells provide the most convenient, consistent, and flexible T cell readout systems for these purposes. If desired, antigen-specific T cell clones can be used in lieu of T hybridoma cells, but T cell clones often give poorer responses than T hybridomas to fixed APCs due to fixation-induced loss of costimulator function. - [Read Presenting Exogenous Antigen to T Cells Protocol]

Category: Chromatography Protocols: Immunoaffinity Chromatography Protocols

Immunoaffinity purification of antibodies is used to purify antigen-specific antibodies from a preparation of polyclonal antibodies.  Such purification is commonly needed in the production of antipeptide antibodies, where it is used to concentrate the desired antibodies and separate them from those raised against carrier proteins.  It is also used for the more general purpose of removing unwanted, nonspecific binding activity from polyclonal antibody preparations. - [Read Purification of Antibodies on an Antigen Column Protocol]

Category: PCR Protocols: Quantitative PCR Protocols

Quantitative PCR involves co-amplification of two templates: a constant amount of a preparation containing the desired target sequence and serial dilutions of a reference template that is added in known amounts to a series of amplification reactions.  The concentration of the target sequence is determined by simple interpolation into a standard curve. - [Read Quantitative PCR Protocol II]

Category: Nucleic Acid Electrophoresis Protocols: Pulsed Field Gel Electrophoresis Protocols

Protocol for restriction endonuclease digestion of DNA in agarose plugs. Genomic DNA isolated from mammalian, yeast, or bacterial cells can be digested with restriction endonucleases by incubating agarose plugs containing the DNA in the presence of the desired enzyme.  After digestion, the DNA can be fractionated by pulsed-field gel electrophoresis and either isolated from the gel or analyzed by Southern Hybridization. - [Read Restriction Endonuclease Digestion of DNA in Agarose Plugs Protocol]

Category: Yeast Cell Culture Protocols: Yeast Media, Solutions and Stocks Protocols

Some yeast strains are unstable (e. g., small YAC-bearing strains) and need to be repurified by streaking on an agar plate and then verifying the genetic content of the isolated colony before proceeding. In cases where the strain is unstable, plan to streak the cells onto the selective medium to retain the desired stock, (however, most strains can be streaked onto the complete medium, YPD). - [Read Streaking Yeast Stocks Protocols]

Category: Reporter Gene Assays: Luciferase Assay Protocols

Transfection of primary leukocytes has traditionally been a challenging but much desired protocol. It allows not only the analysis of cells in a more natural state to a cell line system, it enables the direct comparison of, for e.g. transcriptional activity using luciferase reporters, in immune cells taken from genetically-altered mice. In addition, importantly it allows for "rescue experiments" in knockout cells & the ability to over-express or reconstitute wild-type and/or mutated constructs. - [Read Transfection of Bone Marrow-Derived Mast Cells for Transcription Factor Luciferase Reporter Assays]