McGowan, S. R., Tague, A. J., Kumar, A. A., Ranson, M., Hyland, C. J. T., Ellis, S. R. (2026). Beyond the Fixed Charge: A New On‐Tissue Derivatisation Strategy Employing Photoionisable Chromophores for Mass Spectrometry Imaging of Amino‐Containing Metabolites. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.4492989