Several visualization outputs from Proteo-SAFARI for a UVPD (2 pulses, 1 mJ) mass spectrum of apo-myoglobin (16+, m/z 1060) are displayed in Figure based on the UVPD mass spectrum shown in Figure . The first output is a sequence coverage map (Figure ) which denotes the backbone cleavage sites from which the identified fragment ions originated. A second output is a plot of the m/z error in parts per million determined based on the difference between each of the identified fragment ion isotopes and the corresponding observed peak centroid, as shown in Figure . Figure displays a summary of the normalized intensities of identified fragment ions based on the backbone cleavage position from which they originated. A representation of the observed charge states of each fragment ion based on its backbone cleavage position is shown in Figure . Each of these visualizations provide useful information regarding top-down protein characterization by MS/MS, such as identification of preferential cleavage sites. For example, backbone cleavages are enhanced adjacent to proline residues located at positions 36, 87, 99, and 118 (relative to the Nterminus) in myoglobin, as seen in Figure . The map of fragment ion charge states in Figure provides a means to infer locations of charge sites of the protein, as illustrated for myoglobin.