The Max Planck Institute for Marine Microbiology finished the installation of a NanoSIMS 50/50L in March 2008. The funding for the aquistition of this instrument was provided by the Innovation Fund of the Max Planck Society.
Secondary ion mass spectrometry (SIMS) is a surface analysis technique. It provides information about the lateral distribution of any element and its isotopes as well as a quantitative information about the isotopic composition of a sample. Using a well focused ion beam the sample surface is bombarded with primary ions and secondary ions sputtered from the sample are analysed in a mass spectrometer.
The NanoSIMS 50L is a nanometer scale secondary ion mass spectrometer with both extremely high lateral resolution and high mass resolution. Because of a unique ion optic design, the primary ion beam can be focused to a very small spot down to less than 50nm beam size. This is what allows us to achieve very high lateral resolution analysis. The high mass resolution of the mass analyser allows the separation of the isotope (mass) of interest from interferencing isotopes and/or molecular clusters with very close masses.
The NanoSIMS 50L is equipped with Cs+ and O- primary ion sources, an electron gun for analysis of insulating samples, a secondary electron detector, and a magnetic sector mass analyser with a large version of the magnet and a multi-collection system of 7 detectors all equipped with Faraday cups and electron multiplier detectors. This configuration allows us the possiblity of analysing any mass from helium to uranium as well as molecules and clusters of atoms.
The Max Planck Insitute for Marine Microbiology of Bremen hosts the first NanoSIMS dedicated to environmental microbiology. The NanoSIMS opens new possibilities for coupling phylogenetic identity and metabolic function of single cells in studies of mixed microbial communities from the environment.
Above: Diagram of the major steps employed in single cell analysis by Halogen In situ Hybridization-Secondary Ion Mass Spectrometry (HISH-SIMS). The arrows indicate the order of the main steps, from the environment to the single cell analysis by nanoSIMS.
left - E.coli cells, carbon/nitrogen signal; center - Fluorine signal detected inside the E.coli cells; right - Secondary electron image of the Crocosphaera watsonii cells.
For more details on the nanoSIMS studies being conducted at our institute see:
The Proceedings of the National Academy of Sciences article "A single cell view on the ecophysiology of anaerobic phototrophic bacteria" by Musat et al., (2008) is available via Open Access.
For more information on the unique capabilities of the NanoSIMS 50L in environmental microbiology applications, please visit our project pages.