Secondary Ion Mass Spectrometry (SIMS) is a technique, which can be used to obtain chemical distributions from both the surfaces and 3D volumes of a large number of different types of sample. The NanoSIMS 50 instrument is a state-of-the-art high-resolution SIMS instrument, designed to improve spatial resolution without losing the sensitivity for dilute or trace analytes. The ability of the NanoSIMS to detect trace elements and isotopes with up to 50 nm lateral resolution has provided great potential on molecular imaging applications.
The NanoSIMS enables an alternative strategy for molecular imaging by stable isotopic labeling. Stable isotope labeled molecules can be tracked and quantified in subcellular structures, and they behave almost the same to natural molecules. They are also safe for long-term experiments on animals, even humans. This presentation will report two NanoSIMS applications on molecular imaging with stable isotopic labelling and complementary techniques: (1) visualisation lipid transport through capillary endothelial cells by correlative NanoSIMS and Electron Microscopy analysis [1, 2]; and (2) imaging of interactions between antimicrobial peptides and lipid membranes by correlative NanoSIMS and Atomic Force Microscopy analysis [3]. We will also discuss recent developments of the NanoSIMS improving its ability on detecting trace metal elements, which can be used for direct high-resolution imaging of physiological metals and metal-tagged probes.