title: Western Blotting using the Invitrogen NuPage Novex Bis Tris minigels.
abstract: Western Blotting (or immunoblotting) is a standard laboratory procedure allowing investigators to verify the expression of a protein, determine the relative amount of the protein present in different samples, and analyze the results of co-immunoprecipitation experiments. In this method, a target protein is detected with a specific primary antibody in a given sample of tissue homogenate or extract. Protein separation according to molecular weight is achieved using denaturing SDS-PAGE. After transfer to a membrane, the target protein is probed with a specific primary antibody and detected by chemiluminescence. Since its first description, the western-blotting technique has undergone several improvements, including pre-cast gels and user-friendly equipment. In our laboratory, we have chosen to use the commercially available NuPAGE electrophoresis system from Invitrogen. It is an innovative neutral pH, discontinuous SDS-PAGE, pre-cast mini-gel system. This system presents several advantages over the traditional Laemmli technique including: i) a longer shelf life of the pre-cast gels ranging from 8 months to 1 year; ii) a broad separation range of molecular weights from 1 to 400 kDa depending of the type of gel used; and iii) greater versatility (range of acrylamide percentage, the type of gel, and the ionic composition of the running buffer). The procedure described in this video article utilizes the Bis-Tris discontinuous buffer system with 4-12% Bis-Tris gradient gels and MES running buffer, as an illustration of how to perform a western-blot using the Invitrogen NuPAGE electrophoresis system. In our laboratory, we have obtained good and reproducible results for various biochemical applications using this western-blotting method.
authors.affiliation: Department of Physiology and Biophysics, University of California, Irvine, CA, USA.
authors.forename: Aubin
authors.initials: A
authors.lastname: Penna
authors.forename: Michael
authors.initials: M
authors.lastname: Cahalan
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000379:methods*; D002021:Buffers; D004591:Electrophoresis, Polyacrylamide Gel; D005782:Gels; D006801:Humans; D015203:Reproducibility of Results; D014325:Tromethamine / Q000031:analogs & derivatives
chemical_list: D002021:Buffers; D005782:Gels; D014325:Tromethamine; C026272:Bistris