1 Top-down Analysis of a tRNA Mixture via Ion Trap Collision- Induced Dissociation Teng-Yi Huang, Xiaorong Liang, Jian Liu, Yu Xia and Scott A. McLuckey Department of Chemistry, Purdue University West Lafayette, IN 47907-2084 2 Overview • Purpose: – Characterization of intact tRNA species in a mixture • Method: – Top-down approach – Tandem mass spectrometry – Proton transfer ion/ion reaction • Results: – Gas phase dissociation of oligo-ribonucleotides – Molecular mass determination of tRNAs – Charge reduction of highly charged tRNA anions via proton transfer ion/ion reactions – Intact tRNA sequencing via collision-induced dissociation and proton transfer ion/ion reactions