Distinctive, rapid, and easy labeling of diffuse plaques in the Alzheimer brains by a new methenamine silver stain

Abstract
We have developed a new methenamine silver (MS) stain for detecting diffuse plaques distinctively on paraffin-embedded tissue sections of Alzheimer-type dementia, Down'n syndrome, and mentally normal aged brains. This rapid and easy method selectively labels amyloid-related component of senile plaques, but not of kuru plaques found in Gerstmann-Sträussler syndrome. Our MS stain shows almost the same staining pattern as that of the β protein immunostaining with formic acid pretreatment. Therefore, new MS stain is appropriate to routine or screening studies for senile plaques including diffuse plaques.