2 Dimensional Apparatus
GE Healthcare, USA

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a complex formed facilitating a biological function. The analysis of the proteomic organization of the cell requires techniques conserving the native state of the protein complexes. In 1975, P. H. O'Farrell and J. Klose introduced 2-dimensional electrophoresis which separates proteins according to two independent properties in two different steps: the first dimension step, isoelectric focusing (IEF), separates proteins according to their isoelectric points (pI); the second dimension step, SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE), separates protein according to their molecular weights.  Two-dimensional electrophoresis (2-D electrophoresis) is a powerful and widely used method for the analysis of complex protein mixtures extracted from cells, tissues, or other biological samples. Thousands of different proteins can be separated, and information such as pI of the protein, apparent molecular weight, and amount of each protein can be obtained. The spots will then be used for further analysis like MALDI TOF, LC-MS/MS, etc. 2-dimensional electrophoresis has several applications. For example, by comparing the proteins from normal and cancer cells, cancer-specific proteins can be identified and developed into markers for cancer diagnosis, or drug target for cancer treatment.