Improvement of the two‐dimensional gel electrophoresis analysis for the proteome study of Halobacterium salinarum

Abstract
Inherent problems exist in the use of two‐dimensional gel electrophoresis (2‐DE) for sample preparation and separation of proteins from Halobacterium salinarum. In particular, proteins from cells grown in 25% NaCl are difficult to resolve by 2‐DE due to the abundance of salt. To remove salts, a 3 kDa molecular weight cut‐off column was used. When soluble proteins were separated by 2‐DE, most of the proteins were concentrated in the acidic range. For separation of proteins in the pH 3–6 range, ultrazoom immobilized pH gradient strips were used. In addition, sample separation using a IPGphor/Multiphor combined system was a more effective method for the proteome analysis of acidic proteins than using IPGphor for the isoelectric focusing step.