ESRF, the European Synchrotron 2 articles published in JoVE Chemistry Biological Samples Preparation for Speciation at Cryogenic Temperature using High-Resolution X-Ray Absorption Spectroscopy Caroline Bissardon1, Marie-Pierre Isaure2, Emmanuel Lesuisse3, Mauro Rovezzi4,5, Eric Lahera4,5, Olivier Proux4,5, Sylvain Bohic1,6 1University Grenoble Alpes, INSERM UA7, Synchrotron Radiation for Biomedicine (STROBE), 2 This protocol presents a detailed procedure to prepare biological cryosamples for synchrotron-based X-ray absorption spectroscopy experiments. We describe all the steps required to optimize sample preparation and cryopreservation with examples of the protocol with cancer and phytoplankton cells. This method provides a universal standard of sample cryo-preparation. Biochemistry Cell Culture on Silicon Nitride Membranes and Cryopreparation for Synchrotron X-ray Fluorescence Nano-analysis Caroline Bissardon1, Solveig Reymond1, Murielle Salomé2, Lionel André2, Sam Bayat1, Peter Cloetens2, Sylvain Bohic1,2 1Inserm, UA7, Synchrotron Radiation for Biomedicine (STROBE), Université Grenoble Alpes, 2ID16A Beamline, ESRF, The European Synchrotron Presented here is a protocol for cell culture on silicon nitride membranes and plunge-freezing prior to X-ray fluorescence imaging with a synchrotron cryogenic X-ray nanoprobe. When only room temperature nano-analysis is provided, the frozen samples can be further freeze-dried. These are critical steps to obtain information on the intracellular elemental composition.