Senile Plaques - Identification

Identification

Senile plaques are visible in light microscopy using the staining techniques of silver, Congo red, Thioflavin, cresyl violet, and PAS-reaction. Plaque deposits are also visible through fluorescence and immunofluorescence microscopy. Bielschowsky silver staining was found to be the least efficient means of visualizing senile plaques whereas Campbell and Gallyas silver staining techniques showed improved identification and accuracy. Using Congo red, only one-fourth of senile plaques present were noticeably stained. Senile plaques may also be visualized with an immunostain directed against beta amyloid. The primary problem with the above staining methods is that sections of the neural tissue must be excised from the brain in order to accurately identify senile plaques. This is problematic because removing neural tissue can be as detrimental as the actual plaques themselves.