Two-dimensional gel electrophoresis (2DE) is a powerful and well-established method for high-resolution profiling of proteins. This technique separates complex protein mixtures based on two independent chemical properties: In the first dimension, proteins are separated according to their isoelectric points using a pH gradient contained within a polyacrylamide gel. In the second dimension, these same proteins are further separated according to their molecular weights in a second polyacrylamide gel.