Analysis of biological structures by EELS and energy filtering
ABSTRACT: Electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) and in the energy-filtering transmission electron microscope (EFTEM) each provides important compositional information about biological structures. With recent improvements in instrumentation, detection limits are approaching those predicted by theory. In some applications, single atom detection is feasible for core-loss elemental maps acquired in a STEM equipped with field-emission source, parallel-detection EELS and spectrum-imaging capability. Spectrum-imaging in the EFTEM provides a complementary, quantitative technique for mapping elements that occur at relatively high concentrations over larger specimen areas.