Unit

UNIT 10.2A One-Dimensional SDS Gel Electrophoresis of Proteins

  1. Sean R. Gallagher

Published Online: 1 AUG 2006

DOI: 10.1002/0471142727.mb1002as75

Current Protocols in Molecular Biology

Current Protocols in Molecular Biology

How to Cite

Gallagher, S. R. 2006. One-Dimensional SDS Gel Electrophoresis of Proteins. Current Protocols in Molecular Biology. 75:II:10.2A:10.2.1–10.2A.37.

Author Information

  1. UVP, Inc., Upland, California

Publication History

  1. Published Online: 1 AUG 2006
  2. Published Print: JUL 2006

This is not the most recent version of the article. View current version (1 JAN 2012)

Abstract

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 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.

Keywords:

  • protein;
  • electrophoresis;
  • separation;
  • polyacrylamide;
  • SDS-PAGE