Polarizing Light Microscopy
- 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
- 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
- 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
Editor's Notes
- #4: Light reflect off the objects and then enter in our eye. Then we see the object.
- #26: Gouty deposits may be surrounded by fibrous tissue and be rimmed by histiocytes and giant cells … histiocyte…. gout crystals are long, slender, needle shaped but difficult to visualize with routine staining because they are dissolved during formalin processing
- #28: gout crystals are long, slender, needle shaped
- #33: amorphous pink depositis of amyloid.