Polarized light, birefringence

This is an extracellular deposition of an insoluble protein, which has adopted a (3-sheet structure due to an unknown event that induced misfolding of unstable proteins. The name amyloid has been given according to the amyloid staining properties, which are similar to carbohydrate deposits, e.g., amyloid can be identified with Congo red and seen under polarized light (birefringence test). 

Applications of visible light such as the use of polarized light, birefringence, retardation, angles of extinction, dispersion staining, and phase contrast will be explained, discussed and related primarily to asbestos with some discussion of quartz. 

Aqueous solution studies of sodium poly(styrene sulfonate), in which the electrolyte concentration was varied, again revealed(5-8) that the more extended the polymer conformation the greater its stability. The deformation was predominately extensional in these latter studies gel permeation chromatography(5,6) and polarized light birefringent-pressure drop(7,8) techniques were used to follow degradation. 

Fig. 6. Skin biopsy in ACD. Appearance of an unstained frozen section with polarized light. Birefringent material in the vessel wall and endothelial cells (Fig. 2 from Ruiter 1958)...

The birefringent (BR) modulator makes use of polarized light and tensorial nature of the electrooptic coefficient. For example, poled organic polymer films are characterized by two nonzero components for the electrooptic tensor and parallel and orthogonal to the poling direction,... 

Birefringence is the property of an anisotropic optical media that causes polarized light with one orientation to travel with... 

Starch granules, when observed imder polarized light, exhibit an optical birefringence pattern known as a "Maltese cross" (Fig. 5.4), which implies a high degree of molecular order within the granule (Greenwood, 1979). 

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