What is 2-DGE or 2-DE, DIGE?
2-Dimensional Gel Electrophoresis, with the first dimension being isoelectrofocusing (separation by pI) and the second dimension being SDS-PAGE (separation by size). This method suffers from low sensitivity, low dynamic range (103), difficulty in resolving proteins with extreme mass or isoelectric points, and inability to resolve proteins with low solubility (membrane proteins, hydrophobic proteins). Differential gel electrophoresis (DIGE) has provided improvements over standard 2DE. It involves tagging the two comparison protein mixtures with different fluorescent dyes (Cy2, Cy3, or Cy5), then mixing the solutions and running them on the same gel. Computer software can compare quantitative differences in protein levels in the mixtures.
