This figure is an overhead view of the XFMS experimental setup: A syringe pump pushes samples (proteins or peptides) through a capillary (blue tubing in the figure) and out a jet nozzle. The sample stream from the jet is collected into tubes in a fraction collector, but in the process of falling into the tube, the sample passes through an X-ray beam. The speed of the sample determines how much time it spends in the beam – a longer time in the beam means a higher dose to the sample. The speed can be precisely controlled so that clinically relevant doses are given to samples, and at controlled dose rates. A lens and camera are used to visualize the sample during the experiment to ensure proper alignment, and a photomultiplier tube (PMT) is used to amplify fluorescence from samples to gain additional structural information about the state of the protein or peptide.