Batch Ion-Exchange of soluble C2C12 proteins increases the total number of spots visualized 2.5-fold. Serum-starved C2C12 cells were stimulated for 2 hours with 100 nM IGF-1 and lysed in detergent-free buffer to generate soluble proteins. 100 ug of protein was separated by 2D electrophoresis followed by silver staining (left). Another 100 ug of protein was further fractionated by batch ion-exchange followed by desalting/concentration  before 2D electrophoresis and silver staining. The total amount of protein detected was analyzed using PDQuest software (Bio-Rad).