Quantitative analytical techniques of proteins based on two-dimensional gel electrophoresis

Quantitative analytical techniques of proteins based on two-dimensional gel electrophoresis, depending on the comparing of altered levels of proteins between different samples to obtain quantitative changes, are informative for comprehesive understanding functions and biological mechanism of proteins in cells. Conventional methods in which protein samples are separated on individual gels are introduced, and shortcomings of these methods that limit their application in general 2DE analysis are discussed. More approachs including differential in-gel electrophoresis (DIGE), "differential exposure" approach, and stable isotope approach are stated. The latter methods permitting separation on a single gel containing mixed samples, have superior power in quantitative analysis compared to conventional methods. Various quantitative protocols, advantages and limitations of these protocols as well as further development of quantitative techniques based on 2DE are discussed.