Multi-Color Electron Microscopy of Cellular Ultrastructure Using 4D-STEM

Transmission electron microscopy (TEM) is the primary method for acquiring high-resolution images of cellular ultrastructure of biological samples. Alternatively, fluorescence light microscopy techniques are capable of labeling different cellular components with different dyes, and distinguishing them to form multicolor images; however, at a much lower resolution This serious limitation was recently addressed through the development of "multi-color EM," which uses selective lanthanide ion tagging and electron energy-loss filtered imaging While this technique promises to reveal novel structural information, it depends on a very small fraction of the electrons (typically << 1%) that have lost energy due to a coreloss excitation to create the elemental maps. This makes the method extremely tedious and slow to execute, while producing noisy images that sometimes can be difficult to interpret.