For cells grown in tissue culture, the most useful method of lysis is treating with detergents, as described in this protocol. Non-ionic detergents, such as NP-40, solubilize the plasma and intracellular membranes, break many weak intermolecular bonds, and solubilize most of the commonly studied protein antigens. RIPA lysis buffer may be used as a more rigorous extraction buffer to release all but the insoluble proteins of the cell and to break most weak noncovalent interactions. - [Read Lysing Tissue-Culture Cells for Immunoprecipitation Protocol]
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]
Protocol describes a nondenaturing immunoprecipitation (IP) for mammalian cells. Prefer to use denaturing IPs to recover labeled proteins from pulse-chase experiments. However, the nondenaturing protocol is useful when one wishes to separate soluble from insoluble proteins, or when the antibody being used recognizes a native epitope. - [Read Nondenaturing Protein Immunoprecipitation from Mammalian Cells Protocol]
Protocol for polyclonal antibody production. Very useful for rapid and simple generation of antibodies for western blots, ELISA assays, and immunoprecipitation. Includes: Rabbit Immunization; Initial Preparation; Pre-bleed; Antigen Injection; Monitoring of Titer; Purification of Antibodies. - [Read Polyclonal Antibody Production Protocol]
Protocol was designed to rapidly generate small scale cytosolic extracts of C. elegans for Western or IP (has not been tested for RNA work). The protocol works well for between 50 to 5000 worms and has not been extensively tested on larger a scale, though it should work. Includes: Collection; Sonication; Clearing lysate; Immunoprecipitation. - [Read Preparation of Worm Extracts by Sonication Protocol]
Coimmunoprecipitation is one of the most useful techniques for revealing protein-protein interactions. Good negative controls to verify the specificity of the coimmunoprecipitation procedure are (1) performing the same immunoprecipitation experiment using beads coupled to the preimmune serum and (2) probing the Western blot with antibodies against protein known not to interact with the coimmunoprecipitated proteins under physiological conditions. - [Read Protein Coimmunoprecipitation in Arabidopsis Protocol]
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]
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]
This protocol uses mitogen-activated protein/ERK kinase (MEK) to activate the extracellular-signal-regulated (Erk) mitogen-activated protein (MAP) kinases upon agonist binding to receptors. Protocol includes information about: Harvest, Immunoprecipitation and Kinase Reaction. Also includes following solutions: Laemmli Sample Buffer (1X), ATP Mix, Kinase Buffer (10X), Lysis Buffer. Helpful protocol hints are also included. - [Read Raf-1 Kinase Assay]
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]
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.