Introduction: Why study Nucleic Acids in vacuo? -- Transferring Nucleic Acids to the Gas Phase -- Structure of Nucleic Acids in the Gas Phase -- Interactions between Nucleic Acid Ions and Electrons and Photons -- Gas-phase Spectroscopy of Nucleic Acids -- Fragmentation Reactions of Nucleic Acid Ions in the Gas Phase -- Characterization of Ribonucleic Acids and their Modifications by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry -- Quantification of DNA Damage using Mass Spectrometry Techniques -- Ligand Binding to Nucleic Acids -- MS-based Approaches for Nucleic Acid Structural Determination.