Bruker Daltonics Inc. 1 article published in JoVE Chemistry Histone Modification Screening using Liquid Chromatography, Trapped Ion Mobility Spectrometry, and Time-Of-Flight Mass Spectrometry Meiby Fernandez-Rojas1, Cassandra N. Fuller1, Lilian Valadares Tose1, Matthew Willetts2, Melvin A. Park2, Natarajan V. Bhanu3, Benjamin A. Garcia3, Francisco Fernandez-Lima1,4 1Department of Chemistry and Biochemistry, Florida International University, 2Bruker Daltonics Inc., 3Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 4Biomolecular Sciences Institute, Florida International University An analytical workflow based on liquid chromatography, trapped ion mobility spectrometry, and time-of-flight mass spectrometry (LC-TIMS-ToF MS/MS) for high confidence and highly reproducible "bottom-up" analysis of histone modifications and identification based on principal parameters (retention time [RT], collision cross section [CCS], and accurate mass-to-charge [m/z] ratio).