Outline
     
       Principles of transmission electron microscopy.
     
       Cell as subcompartments.
     
       Electron microscopy and light microscopy for storage 
     disorders.
     
       Immunoelectronmicroscopy, 3D reconstruction, and scanning 
     electron microscopy as well as new techniques 
     (nanotechnology?) for subcellular compartment storage disorders 
      
           Electron Microscopy at Glance
    
      It is a scientific instrument that use a beam of highly energetic 
    electrons to examine objects on a very fine scale.
    
      Wavelength of electron beam is much shorter than light, 
    resulting in much higher resolution.
    
      Two different types of EMs are: 
      
        Transmission Electron Microscope (TEM): TEM allows 
      one the study of the inner structure and contours of objects 
      (tissues, cells, virusses)
      
        Scanning electron Microscope (SEM): SEM is applied to 
      visualize the surface of tissues, macromolecular aggregates 
      and materials.
      Transmission Electron Microscope (TEM)
     
       Electrons scatter when they pass through thin sections of a 
     specimen.
     
       Transmitted electrons (those that do not scatter) are used to 
     produce image.
     
       Denser regions in specimen, scatter more electrons and appear 
     darker.
          Transmission Electron Microscope (TEM)
       
         Gun emits electrons
       
         Electric field accelerates 
       
         Magnetic (and electric) field control 
       path of electrons
       
         Electron wavelength @ 200KeV:  
           -12
       2x10  m
       
         Resolution normally achievable @ 
                      -10
       200KeV:  2 x 10  m   2Å
              Electron Microscope vs. Light Microscope
                 Electron Microscope                           Light Microscope
         
            High resolution, higher                  
                                                        Useful magnification (only up to 
         magnification (up to 2 million times).      1000-2000 times).
         
           View the 3D external shape of an          
                                                        3D external shape is not visible 
         object (SEM).                               by optical microscopy.
         
            2 different types of electron            
                                                        2 types of microscopes: are 
         microscopes: scanning electron              compound microscopes and stereo 
         microscopes (SEM) and transmission          microscopes (dissecting 
         electron microscopes (TEM).                 microscopes).