Polyacrylamide gel electrophoresis (PAGE) is probably the most general and widespread protein separation technique. This simple method is used in almost every molecular biology and biochemistry laboratory to monitor protein experiments, including consecutive stages of protein purification. PAGE may even be the final step of a purification protocol. Over the last decade, two-dimensional gel electrophoresis (2-D-PAGE) (1 ) has been developed, and applied to the separation of crude protein mixtures from organelles, tissues, and whole organisms (2 ).
