microscopes

microscopes

1. light

   • resolution=200nm
     • bulb>
       • stage>
         • condenser lens
           • specimen
             • objective lens
               • eyepiece lens
                 • x10
               • x4, 10, 40, 100
   • mag= x1500
   • staining- coloured dyes bind to biological organisms
   • sectioning- specimens embedded in wax

2. electron microscopes

   • TEM & SEM
     • X500,000. RS=0.2nm
       • beam passes through
         • 2d images
     • x100,000 RS=0.2nm
       • beam bounces off, produces 3d images
   • electrons have a wavelength of 0.004nm
   • limitations: need a high degree of skill and training.
     • very expensive
       • air molecules deflect electrons so needs to be done in a vaacuum