Polarimetric imaging of amyloid.

New developments in optical microscopy are discussed with relevance to the imaging of amyloid plaques that are pathognomonic of a variety of degenerative disorders. We present the results of linear birefringence, linear dichroism, and circular dichroism imaging of Congo red stained plaques ex vivo and in vitro. A new technique for measuring rapid changes in linear anisotropies is introduced. The application of polarimetric imaging as demonstrated here can be extended to broader pathological practice since polarimetric measurements are sensitive to transformations in tissues that are specific disease signatures.