Metals play an essential role in cellular homeostasis and are key components of several formulations currently used in the clinic. Synchrotron‐based X‐ray microscopy at submicron resolution is a powerful approach to map intracellular elemental distributions and to monitor how these patterns change upon genetic or pharmacological perturbations. However, existing sample‐preparation protocols often rely on costly and highly specialized equipment for vitrification and dehydration, limiting their widespread adoption. Here, we present an adapted plunge‐freezing and freeze‐drying workflow that enables the preparation of mammalian cell samples for X‐ray fluorescence (XRF) and X‐ray absorption spectroscopy (XAS) studies with submicron resolution in a cost‐effective and versatile manner. Furthermore, we define acquisition parameters optimized for the reliable detection of low‐abundance metals, such as endogenous iron. We anticipate that this accessible protocol will facilitate the broader implementation of synchrotron‐based inner‐shell spectromicroscopy in cell biology.
Tamargo‐Azpilicueta et al. (2026) studied this question.