complexes Protocols

Category: Protein Protocols: Immunoprecipitation Protocols

Antibody-antigen complexes are removed from solution by addition of an insoluble form of an antibody binding protein such as Protein A, Protein G or second antibody. Immunoprecipitation protocols / methodology and technical background information. P.J. Ha - [Read Analysis of Proteins by Immunoprecipitation]

Category: Plant Biology Protocols: Plant Proteins, Peptides and Antigens

BN-PAGE has become the method of choice for the investigation of the respiratory protein complexes of the electron transfer chains of a range of organisms. It allows the separation in two dimensions of extremely hydrophobic protein sets for analysis and also provides information on their native interactions. In this review we discuss the capabilities of BN-PAGE in proteomics and the wider investigation of protein:protein interactions with a focus on its use and potential in plant science. - [Read Blue-Native PAGE in Plants: A Tool in Analysis of Protein-Protein Interactions]

Category: Immunology: Immunoprecipitation Protocols: Chromatin Immunoprecipitation Protocols

Protocol describes the use of chromatin immunoprecipitation technology (ChIP) to analyze interactions of proteins or protein complexes with DNA in vivo. In this approach, the material is fixed with formaldehyde to preserve DNA-protein and protein-protein associations, the cells are lysed, and the chromatin is cut and solubilized. The chromatin suspension is immunoprecipitated with an antibody against the protein(s) of interest, and the coimmunoprecipitated DNA fragments are analyzed. - [Read Chromatin Immunoprecipitation (ChIP) of Protein Complexes Protocol]

Category: Epigenetics and Methylation Protocols: ChIP Chromatin Immunoprecipitation Protocols

Chromatin immunoprecipitation protocol to analyze histone modifications in Arabidopsis thaliana. Werner Aufsatz, Matzke Lab. Gregor Mendel Institute of Molecular Plant Biology, Austria. Includes Chromatin Crosslinking, Chromatin preparation, Pre-clearing and immuno precipitation (IP), Collection,washes and elution of immune complexes, Reverse crosslinking and DNA cleanup - [Read Chromatin immunoprecipitation protocol to analyze histone modifications in Arabidopsis thaliana]

Category: DNA Protocols: Chromatin Immunoprecipitation Protocols

ChIP assay protocol with 2 steps: in vivo formaldehyde cross-linking of whole cells and protein-protein and protein-DNA interactions, followed by immunoprecipitation of protein-DNA complexes with specific antibodies from sonicated extracts. Breeden Lab - [Read Chromatin IP (CHIP assay)]

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: Immunology: Immunoprecipitation Protocols

For many sources of antigens, one useful method of lysis is to treat cells with harsh, denaturing solutions to release most of the protein antigens, as described here. The lysates are then diluted to reduce the denaturing conditions to levels that are suitable for the formation of antibody-antigen complexes. The resulting solution is precleared prior to immunoprecipitation. - [Read Immunoprecipitation: Denaturing Lysis Protocol]

Category: Protein Protocols: Lowry Protein Assay

Lowry Protein Assay. The Lowry procedure is one of the most venerable and widely-used protein assays, being first described in 1951 [Lowry et al., J. Biol. Chem. 193: 265-275 (1951)]. Under alkaline conditions, copper complexes with protein. When folin phenol reagent (phospho-molybdic-phosphotungstic reagent) is added, the Folin-phenol reagent binds to the protein. Bound reagent is slowly reduced and changes color from yellow to blue. P.J. Hansen, Dept. of Animal Sciences, University of Florida. - [Read Lowry Protein Assay]

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: 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: Signalling Signal Transduction Protocols

Protocol describes a competitive ligand binding assay for cortical neurotrophin receptors. Following binding in the presence of competitor, the bound radiolabeled ligand is cross-linked to the receptor. The cells are lysed and the ligand-receptor complexes are immunoprecipitated using a pan-trk (tyrosine kinase receptor) antibody. Protocol includes:Preparation of Cortical Tissue for Competitive Crosslinking, Competitive Binding, Crosslinking Ligand to Receptor, Lysis and Immunoprecipitation etc - [Read Protocol for Competitive Ligand Binding to Cortical Receptor using Crosslinking]

Category: Protein Protocols: Immunoprecipitation Protocols: Immunoprecipitation Troubleshooting

Troubleshoot Immunoprecipitation. Chemicon. The most common challenge with immunoprecipitation is trying to lower the number and type of background proteins that contaminate the washed immune complexes. Suggestions for decreasing background in IP. - [Read Troubleshoot Immunoprecipitation]

Category: Western Blot Protocols: Antigen Detection Methods Protocols

Use of the chemiluminescence-producing alkaline phosphatase substrate 3-(4-methoxyspiro[1,2-dioxetane-3,2'-tricyclo-[3.3.1.1(3,7)]decan]-4-yl)phenyl phosphate (AMPPD, also known as adamantyl-1,2-dioxetane phosphate), or its dioxetane relatives provides a substantial increase in sensitivity over colorimetric substrates and radiochemical methods currently used for the detection of antigen-antibody complexes immobilized on nylon or PVDF membranes. - [Read Western Analysis Using the Chemiluminescent Alkaline Phosphatase Substrate CSPD Protocol]