Applied Biosystems (Foster City, CA) has updated the 4800 MALDI TOF/TOF mass spectrometer and enhanced ProteinPilot software, which augments the performance of the 4800 Plus, for quantitative insight into proteomics. The 4800 Plus MALDI TOF/TOF Analyzer can identify thousands of proteins in a biological sample. The software maximizes the information that can be obtained from the combination of the 4800 Plus and iTRAQ reagents.