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.

7. Key Component Of Polarizing
Microscope
Polarizer Analyzer

8. Analyser in holder

9. analyzer
polarizer

10. • 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.

12. But something we need to know:

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

14. 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.

17. • When the waves emerge from the crystal they
will be polarized at 90o 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.

18. Interferance

19. 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.

20. Too Difficult ?

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

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

24. Tophi as an initial manifestation of gout

25. Tophi as an initial manifestation of gout

27. Tophi as an initial manifestation of gout

28. Gout and Pseudogout

29. Urate crystal scrap

30. Urate crystal scrap

31. Urate crystal scrap

32. Amyloid
H&E Stain

33. Amyloid
Congo Red Stain

34. Amyloid
Apple green birefringence

35. Silica granuloma

36. Silica granuloma

37. Silica granuloma

38. FB in knee

39. FB in knee

40. FB in knee

41. Suture material

42. Suture material

43. Suture material

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

45. THANK YOU