LR Gold embedding of nervous tissue for immunoelectron microscopy studies.

A major drawback of all acrylic resins commonly used for post-embedding immunocytochemical studies of the central nervous system is the disruption of the ultrastructural morphology, due to the high lipid content of neural tissue. We have investigated the suitability of the acrylic resin LR Gold, which has been employed recently for immunogold labeling studies in several non-neural tissues. Optimal preservation of both antigenicity and ultrastructure of nervous tissue was obtained after en bloc staining with uranyl acetate, followed by total dehydration in acetone and curing at low temperature. Cell membranes and myelin sheaths, which are usually lost with other acrylic resins, were well maintained. The degree of antigenicity of LR Gold-embedded tissues was comparable to that of LR White-embedded one, but the morphologic detail was much better preserved. The use of LR Gold is particularly advantageous for studying neurodegenerative disorders such as Alzheimer disease.