Instrumentation:
We run a Thermo Finnigan LCQ Decca XP Plus ion trap mass spectrometer with NanoLC/ESI, ESI, and AP/MALDI  ion sources. The Finnigan LCQ Deca XP mass spectrometer in NanoLC/ESI mode is well suited for the identification of peptides in complex mixtures. Data analysis is speeded by an IBM 16 node computational cluster.