complex Protocols

Category: Cell Organelle Protocols: Subcellular Fractionation Protocols

Protocol describes systems in which the membranes are allowed to float through a density gradient from a dense load zone. This is an ideal format. - [Read A Self-generated Gradient to Discriminate a Cytosolic or Membrane Location of Large Protein Complex]

Category: Molecular Biology Protocols: Carbohydrate Protocols

High performance liquid affinity chromatography (HPLAC) is a useful procedure to investigate he interactions between carbohydrate binding protein and their ligands. Technical requirements are similar to conventional HPLC. HPLAC can screen and separate natural ligands from complex biological mixtures. WeiTong Wang~GlycoTech Corporation, Rockville, Maryland - [Read Analysis of Oligosaccharide Ligands by High Performance Liquid Affinity Chromatography]

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

Complex yeast media protocols. Including: YPAD Medium or Also Called YPD plus Adenine; Synthetic Complete Drop Out (SC drop-out)Medium; Synthetic Complete drop-out Medium Mix (SC drop-out). - [Read Complex Yeast Media Protocols]

Category: Transfection Protocols

Protocol should be viewed as a starting point for systematic optimization of transfection mediated by lipofecting agents. Once a positive signal has been obtained from a transfected plasmid carrying a standard reporter gene, optimal conditions for transfection can be established by systematic variation of parameters such as the initial cell density, the amount and purity of DNA, the media and serum, and the time of exposure of the cells to the cationic-lipid-DNA complex. - [Read DNA Transfection Mediated by Lipofection Protocol]

Category: Mouse Protocols: Mouse Genetics Protocols

Protocol describes a method for electroporating DNA into ES cells, as well as selection methods. Pilot studies should be performed to optimize the conditions for each DNA construct. The selection method described here is one of the most complex. It involves targeting constructs in which the bacterial neomycin-resistance gene disrupts the coding sequence of the mouse gene. - [Read Electroporating DNA into Embryonic Stem (ES) Cells and Selection Methods Protocol]

Category: Nucleic Acid Electrophoresis Protocols: DNA Electrophoresis Protocols: DNA Electrophoresis in Polyacrylamide Gels Protocols

Protocol exploits differences in electrophoretic mobility through a nondenaturing polyacrylamide gel between a rapidly migrating target DNA and a more slowly migrating DNA-protein complex. - [Read Gel Retardation Assays for DNA-binding Proteins Protocol]

Category: Genetics and Genomics: Genotyping Protocols: Mutation Detection Protocols

In this method, the nuclease BAL 31 is used to make uni- or bidirectional deletions in a segment of cloned DNA. BAL 31 is a complex enzyme and tends to digest a population of double-stranded DNA targets in an asynchronous fashion, Deletions created by BAL 31 are therefore far more heterogeneous in size than those created by processive enzymes such as exonuclease III. - [Read Generation of Bidirectional Sets of Deletion Mutants by Digestion with BAL 31 Nuclease Protocol]

Category: Staining Protocols: Gram Staining Protocols

Gram-positive and Gram-negative organisms form a complex of crystal violet and iodine within the bacterial cell during the Gram-staining procedure. Gm+ organisms are thought to resist decolorization by alcohol or acetone because cell wall permeability is markedly decreased when it is dehydrated by these solvents. Thus, the dye complex is entrapped within the cell, resist being washed out by the solvents, and Gm+ bacteria remain purple following this differential stain. - [Read Gram Staining Protocol]

Category: Microscopy Protocols: Electron Microscopy Protocols

The scanning transmission electron microscope precision and reproducibility of mass measurements are comparable with those of the analytical ultracentrifuge, the possibility of determining the mass not only of entire supramolecular assemblies but also of their distinct components has opened exciting new avenues which have occasionally been entered but are not yet fully explored. Includes: Principle and application (The GroEL:GroES complex). - [Read Imaging and Measuring Biomolecules & Their Assemblies by Scanning Transmission Electron Microscopy]

Category: Western Blot Protocols

Protein immunoprecipitation can be a useful preparative step for immunoblotting.  For very rare proteins, the protein of interest can be purified and concentrated by standard immunoprecipitation techniques before immunoblotting.  In addition, protein-protein interactions can be tested with an immunoprecipitating antibody that is specific for one protein of a complex and an immunoblotting antibody that is specific for a second member of the complex. - [Read Immunoblotting: Preparing Immunoprecipitated Proteins Protocol]

Category: Protein Protocols

Protocol for studying quantitative relationships of proteins in a complex. - [Read Immunodepletion Protocol]

Category: Immunology: Immunoprecipitation Protocols

Protocol for immunoprecipitation of mRNA-protein complexes. In this protocol, an antibody targeting an RBP of interest is used to immunoprecipitate the RBP and any interacting molecules from a cell lysate. Reverse transcription followed by PCR is then used to identify individual mRNAs isolated with the RBP. This method focuses on examining an association between a specific RBP-mRNA complex, and it is best suited for a small scale screening of known or putative binding partners. - [Read Immunoprecipitation of mRNA-Protein Complexes Protocol]

Category: Molecular Biology Protocols: Carbohydrate Protocols

Immunostaining thin layer chromatograms TLC is a very sensitive detection technique of functionally active carbohydrate ligands of protein receptors. Carbohydrate structures are detected in glycolipids from complex mixtures of molecules extracted from the relevant target tissue. Proteins analyzed can be antibodies, chimeric Ig proteins, selectins, lectins, toxins, and other carbohydrate binding proteins. John L. Magnani~GlycoTech Corporation, Rockville, Maryland - [Read Immunostaining Thin Layer Chromatograms Of Glycolipids]

Category: Immunology: Mononuclear Cell Isolation Protocols: B Lymphocyte Isolation Protocols

A flow cytometry technique is presented, which results in the selection and isolation of two populations of cells from a complex mixture based on physical properties (e.g., size and internal granularity) and correlated expression of several surface molecules - [Read Isolation of Ly-1+/CD5+ B Cells by Cell Sorting Protocol]

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

The yeast, Saccharyomyces cerevisiae, has become an important organism in molecular, biochemical, and genetic analysis. The organism has specific requirements for growth under a variety of conditions. The media, both liquid and solid, simple, define, and complex are describe in this unit. Also included are methods for handling, storing, and shipping stock of yeast. - [Read Media and Culture of Yeast Protocol]

Category: Immunology: Immunoprecipitation Protocols: Immunoprecipitation of Radiolabeled Cells Protocols

Cells incorporate 35S-methionine or cysteine during the protein synthesis. Thus it is essential to use Met,Cys-free medium and dialyzed FCS during the labeling. Short period of incubation with 35S-methionine or cysteine will result in radiolabeling (pulse), and additional incubation with excess concentration of unlabeled Met+Cys (chase) is needed for complex glycoproteins like integrins to get expressed as a maturated form. - [Read Metabolic Labeling & Immunoprecipitation Protocols]

Category: Bacterial Protocols

Ice tea has a complex composition, which leads to reduced filterability, and a decrease in sample throughput. Its composition can generate background or false positive signals. It is also well known that ice tea contains molecules that can inhibit the bioluminescence reaction, which can generate false negative results. The aim of this study was to develop a protocol that was able to neutralize these affects and enable faster detection of contamination. - [Read Microbial Detection in Ice Tea Using the Millipore Milliflex Rapid Microbiology Detection System]

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

Human tissues are comprised of multiple interacting cell populations in a complex three dimensional arrangement with each cellular phenotype determined by a unique profile of mRNA and protein expression. Before microdissection techniques were developed, the only analysis tools for phenotypic studies were primarily immunohistochemistry and in-situ hybridization. While useful, these tools are limited to single gene analysis and, in general, do not allow qualitative studies. - [Read Microdissection Overview]

Category: Immunology: T Cell Protocols

T cell hybridomas can be obtained by fusing activated T cells with tumor cells. A heterogeneous population of hybridomas can be cloned by limiting dilution to obtain hybridomas that express specificity to one T cell receptor (TCR). Protocol describes cell fusion and selection of T cell hybridomas. A protocol is provided for screening of T cell hybridomas for expression of the CD3-TCR complex by flow cytometry analysis. - [Read Production of Mouse T Cell Hybridomas Protocol]

Category: Immunology: Immunoprecipitation Protocols

Immunoprecopitation method, the protein from the cell or tissue homogenate is precipitated in an appropriate lysis buffer by means of an immune complex which includes the antigen (protein), primary antibody and Protein A-, G-, or L-agarose conjugate or a secondary antibody-agarose conjugate - [Read Protocol Immunoprecipitation]

Category: Genetics and Genomics: Genotyping Protocols

Describe the current efforts to identify and characterize the large number of SNP's required and discuss the practicalities of association studies for the identification of genes involved in complex traits. - [Read Single Nucleotide Polymorphisms as Tools in Human Genetics]

Category: DNA Protein Interactions Protocols

The multiprotein-DNA complex of interest is formed using the site-specifically derivatized DNA fragment.  The complex is then UV-irradiated, initiating covalent cross-linking with proteins in direct physical proximity to the cross-linking agent.  Extensive nuclease digestion is performed to eliminate uncross-linked DNA and convert cross-linked DNA to a cross-linked, radiolabeled nucleotide "tag." - [Read Site-Specific Protein-DNA Photo-Cross-Linking: Analysis of Structural Organization of Protein-DNA]

Category: Cell Biology and Cell Culture: In Vitro Reconstitution Protocols

Small ubiquitin-like modifier (SUMO) is a small molecule, but has a variety of regulatory functions in cells. SUMO modification is involved in transcriptional regulation, subcellular localization, and protein-protein interactions. SUMO conjugation requires sequential E1-dependent activation, E2-dependent conjugation, and E3-dependent ligation steps. Protocol includes: In vivo and in vitro SUMOylation assay and deSUMOylation assay. - [Read Sumoylation and Desumoylation Assays for a Chromatin-Remodelling Complex In Vivo and In Vitro]

Category: Bioinformatics

Searches are not constrained for only tryptic peptides, and indexed databases (databases only containing tryptic peptides) are not used. In cases where there are very complex mixtures, such as cell lysates, nonspecific cleavages can occur. Therefore, nontryptic peptides would be missed in the database search. - [Read The Use of Mass Spectrometry in Proteomics: Database Searching]