Effects of FIGE on 2D PAGE analysis of rat liver lysates. Comparison of 2D PAGE images of rat liver lysate under FIGE (a) and CFE (b) conditions. Each gel represents 100 μg of rat liver lysate separated by isoelectric focusing (IEF) using a non-linear pH 3–10 IPG strip in the first dimension and a Criterion precast SDS-10–20% PAG in the second dimension at room temperature. Control denotes CFE and pulsed denotes FIGE with a t a/t r of 400/106 msec in the second-dimension separation. Gels were stained with Coomassie blue. Spots selected for LC-MS/MS analysis are denoted by numbers, and A denotes the internal calibrator (see also Table 3). The internal calibrator is the internal controls for equivalent sample loading in both control and pulsed conditions.