ABSTRACT
Two-dimensional gel electrophoresis is the most powerful protein separation tech nique and is applicable to soluble as well as membrane proteins . By combining isofocusing with sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE), a high resolution and a high separation capacity is obtained. These properties make two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) the method of choice for the analysis of very complex mixtures. More than a thousand radioactively labelled proteins can be resolved and detected in a single two-dimensional gel (O'Farrell, 1 975 ; Garrels,
Cellular extracts of proteins are frequently subjected to 2D-PAGE. The resulting protein pattern is a reflection of the protein composition of the analysed cells . The intensity of each protein spot in the protein gel is correlated with its presence in the analysed tissue and the expression of its corresponding gene. 2D-PAGE of a cellular extract from a tissue which has been subjected to in vivo labelling with a radioactive amino acid gives insight into the translation of genes and/or the cellular turnover of the proteins.
