In vitro ADP-ribosylated Src-K295M was separated by SDS-PAGE and the Coomassie stained protein band excised and digested with either trypsin, thermolysin or elastase. All digests were analysed by nanoLC-MS/MS using Higher-energy C-trap Dissociation (HCD) as well as Electron-Transfer Dissociation (ETD) fragmentation.