UNIT 6.1 One-Dimensional SDS Gel Electrophoresis of Proteins
Published Online: 1 DEC 2007
Copyright © 2007 by John Wiley and Sons, Inc.
Lab Protocol Title
Current Protocols in Cell Biology
How to Cite
Gallagher, S. R. 2007. One-Dimensional SDS Gel Electrophoresis of Proteins. Current Protocols in Cell Biology. 37:6.1:6.1.1–6.1.38.
- Published Online: 1 DEC 2007
- Published Print: DEC 2007
Electrophoresis is used to separate complex mixtures of proteins (e.g., from cells, subcellular fractions, column fractions, or immunoprecipitates), to investigate subunit compositions, and to verify homogeneity of protein samples. It can also serve to purify proteins for use in further applications. In polyacrylamide gel electrophoresis, proteins migrate in response to an electrical field through pores in a polyacrylamide gel matrix; pore size decreases with increasing acrylamide concentration. The combination of pore size and protein charge, size, and shape determines the migration rate of the protein. In this unit, the standard Laemmli method is described for discontinuous gel electrophoresis under denaturing conditions, that is, in the presence of sodium dodecyl sulfate (SDS). Both full-size and minigel formats are detailed. Several modifications are provided for specific applications. For separation of peptides and small proteins, the standard buffers are replaced with either a Tris-tricine buffer system or a modified Tris buffer in the absence of urea. Continuous SDS-PAGE is a simplified method in which the same buffer is used for both the gel and the electrode solutions and the stacking gel is omitted. Other protocols cover the preparation and use of ultrathin gels and gradient gels, and the simultaneous preparation of multiple gels. Curr. Protoc. Cell Biol. 37:6.1.1-6.1.38. © 2007 by John Wiley & Sons, Inc.