Polarizing Light Microscopy

Basic principle of polarizing light microscopy and histopathological example.

1. Polarizing Light Microscopy Presented by Supervised by Dr Faruq Ahmed Rezwan Prof. Mohammad Kamal MD Resident (Pathology) Phase A BSMMU

2. Polarizing Light Microscopy It is a technique where polarized light is used in microscope to evaluate composition and three dimensional structure of anisotropic specimen.

3. How we see.

4. Pathway of light in Microscope

5. Normal light vibrate in many plane or vibration direction. In polarized microscope, a polarizer is used which allow passage of light of one vibration direction.

6. Key Component Of Polarizing Microscope Polarizer Analyzer

7. Analyser in holder

8. analyzer polarizer

9. Polarizer and analyzer (which is also a polarizer) are placed at right angle. So, normally no light will pass through and the viewer will only see darkness.

10. But something we need to know:

11. Anisotropic substance Anisotropic substances are “direction-dependent” – that is, they do not behave the same way in all directions.

12. Birefringence Birefringence is defined as the double refraction of light due to differences in refractive index observed in anisotropic substance. Here , incident ray of light is split into two rays, called an slow ray and an fast ray .

13. When the waves emerge from the crystal they will be polarized at 90 o to each other . But , when object is at 45°, the phase difference between the two rays which can develop are able co combine in the analyzer and form a visible image- interferance .

14. Interferance

15. How to use. Analyzer is pushed completely in place. Polarizer is placed and is rotated until the field of view become dark. Specimen is placed on the stage and polarizer is rotated to evaluate the specimen.

16. Too Difficult ?

17. No it isn’t. Stay awake and have a look at this video

18. Uses Commonly evaluated materials are: Gout crystals Urine crystals Amyloid . Foreign Body Suture material Bone Teeth Striated muscle

19. Tophi as an initial manifestation of gout

20. Tophi as an initial manifestation of gout

21. Tophi as an initial manifestation of gout

22. Gout and Pseudogout

23. Urate crystal scrap

24. Urate crystal scrap

25. Urate crystal scrap

26. Amyloid H&E Stain

27. Amyloid Congo Red Stain

28. Amyloid Apple green birefringence

29. Silica granuloma

30. Silica granuloma

31. Silica granuloma

32. FB in knee

33. FB in knee

34. FB in knee

35. Suture material

36. Suture material

37. Suture material

38. Courtesy to Prof. Mohammed Kamal sir for the picture of slide no. 7, 9, 24- 28, 32-43.

39. THANK YOU