A method for the detection of amyloid in human tissue embedded in epon using a combination of polarizing light microscopy and electron microscopy

This paper describes a method for demonstrating amyloid in human tissue embedded in epon using a combination of congo red staining and polarizing microscopy. The method involves the removal of the embedding medium from semi-thin sections prior to staining with congo red and examination in the polarizing microscope. Typical apple green birefringence was detected in areas of amyloid deposition; these areas were mapped for selective trimming and ultra-thin sections taken serially were examined in the electron microscope. The method was found to be reliable, easy to use and particularly of value as a sampling procedure prior to investigation in the electron microscope.