title: An Affordable, Indigenous Polarizer-Analyser System with Inbuilt Retardation Plate Function to Detect Birefringence using 3D Glasses: An Experience.
abstract: BACKGROUND
  Polarizing microscope plays a vital role in few but unique situations. A pair of cross polarizers is used to confirm the presence of birefringent substances. Also, a red retardation plate is needed to evaluate the sign of birefringence. However, a polarizing microscope especially with retardation plate is very expensive. Thus, an affordable yet effective substitute using the 3D Polaroid glasses used for '3D movies' would enable widespread use of the polarizing system.
  
  
  OBJECTIVE
  To study the use of 3D polaroid glasses procured from cinema halls in detecting birefringence substances and to study the red retardation plate function in them.
  
  
  METHODS
  Passive 3D Polaroid glasses were procured from cinema halls. They were arranged in aspecific manner to obtain polarized light. Red retardation plate function can be obtained by changing the arrangement of the glasses. These glasses were used with various available models of different light microscope manufacturers. Various specimens observed included amyloid deposits, woven and lamellar bone, skeletal muscle striations, urate crystals, cholesterol crystals, suture material and glove powder. The comparison was based on subjective interpretation of intensity and quality of birefringence. Sign of birefringence was also determined whenever relevant.
  
  
  RESULTS
  The birefringence observed by our system was comparable to the commercially available polarizing system with respect to intensity and quality. Also, there were no false positive /negative results when compared with the commercial Polarizing microscope. Moreover, the system had an inbuilt red retardation plate to determine sign of birefringence.
  
  
  CONCLUSIONS
  The system is efficient, cheap, easily accessible, portable and compatible with all models of light microscopes.
authors.affiliation: Resident, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Desai Parth
authors.initials: DP
authors.lastname: Anil
authors.affiliation: Resident, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Dange Prasad
authors.initials: DP
authors.lastname: Sudhir
authors.affiliation: Resident, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Annapurna
authors.initials: A
authors.lastname: Saksena
authors.affiliation: Professor, Department of Pathology, Maulana Azad Medical College , New Delhi, India .
authors.forename: Nita
authors.initials: N
authors.lastname: Khurana
keywords: 3D Polaroid glasses; Amyloid; Polarizing microscope; Red retardation plate; Urate crystal