While advances in mass spectrometry have been critical, developments made in two-dimensional PAGE (2D-PAGE) have also played a major role in enabling proteomics. A large number of samples can be processed using a single gel plate, facilitating the direct comparison of specimens processed under identical conditions; and, most importantly, the flat slab permits the application of 2-D separations. These insightful preferences have been proven true and are practiced today in many bioanalytical laboratories. Another advancement in 2-D gel separations was introduced in 1972 by Wright, who used a 4.75% (2% cross-linkage) polyacrylamide gel column in the first dimension, which was then removed from the glass cylinder and laid on the upper edge of a 2% gradient slab. Following electrophoresis, the gel slab was placed in a staining solution, resulting in the visualization of 112 resolved human serum proteins.The 2-D SDS-PAGE and 2D-DIGE approaches to protein profiling are accessible and economical methods that possess high resolving power and enable the detection of hundreds of proteins on a single gel plate.
