1. Imaging with Waves

2. How good is the eye? 100 - 50  m resolution

3. Magnification

4. Seeing small things Antonie van Leeuwenhoek

5. The inverted telescope

6. Robert Hooke

7. Seeing sharper

8. Modern optical microscopy

9. Focusing down Airy Disk 0.61 /NA NA = nsin  22 Resolution ~ 300 nm

10. The diffraction limit Objects spaced apart by less than d~ /2NA cannot be resolved individually! Ernst Abbe (1840-1905)

11. Imaging with the diffraction limit ObjectImageFocal spot Images can be improved by using shorter wavelengths

12. CD versus DVD 7x more data on DVD because of different wavelength! 780 nm650 nm (Blu-Ray DVD uses 405 nm, 6x more data than DVD)

13. UV lithography

14. Superresolution

15. Single molecules

16. Seeing single molecules at work

17. Seeing smaller things using EM radiationusing particles of particles: Electron with v = 1.0 x 10 5 m/s:

18. Electron Microscopy Resolution ~ 0.2 nm

19. Electron Microscopy

20. Cryo-Electron Microscopy

22. Viral DNA portal protein

23. What are X -rays? Wilhelm Conrad Röntgen (1845-1923) Electromagnetic radiation with wavelength of ~10 -10 m

24. Focusing or diffracting? Bragg diffractionDiffraction pattern 2d sin  = n

25. X-ray crystallography

26. Protein structure determination X-ray crystallography reveals electron densities

27. Protein structure determination

28. No longer a mystery

29. DNA polymerase on the DNA backbone