Identification of DNA-protein complexes using an improved, combined western blotting-electrophoretic mobility shift assay (WEMSA) with a fluorescence imaging system

Mol Biosyst. 2012 Apr;8(5):1389-95. doi: 10.1039/c2mb05500g. Epub 2012 Feb 22.


Electrophoretic Mobility Shift Assays (EMSAs) are used to detect DNA-protein interactions. With this type of assay it is difficult to distinguish between specific and non-specific DNA-protein complexes or to define which protein binds to the DNA. Here we describe a novel Western blot-combined EMSA (WEMSA) variant for a fluorescence imaging system which permits easy identification of specific DNA-protein-complexes. This method also allows investigation of several DNA-protein complexes in parallel. We have identified and distinguished clearly between the SP1- and EGR1-DNA-protein complexes which exhibit overlapping binding to the GC-BOX of the mPGES-1 promoter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blotting, Western / methods*
  • DNA / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Early Growth Response Protein 1 / metabolism
  • Electrophoretic Mobility Shift Assay / methods*
  • Fluorescence
  • HeLa Cells
  • Humans
  • Intramolecular Oxidoreductases / metabolism
  • Luminescent Measurements / methods*
  • Molecular Sequence Data
  • Promoter Regions, Genetic / genetics
  • Prostaglandin-E Synthases
  • Protein Binding
  • Sp1 Transcription Factor / metabolism


  • DNA-Binding Proteins
  • EGR1 protein, human
  • Early Growth Response Protein 1
  • Sp1 Transcription Factor
  • DNA
  • Intramolecular Oxidoreductases
  • PTGES protein, human
  • Prostaglandin-E Synthases