Alzheimer's disease is characterised by a gradual decline of the cognitive functions and it is accepted that one of its hallmarks is the accumulation of insoluble proteinaceous deposits called amyloid fibrils. Originally thought to be carbohydrate in nature as they could be stained in tissues with iodine, they were called amyloids as iodine was a well-known stain for polysaccharides such as amylose. It was later discovered they were actually constituted of proteins fibres (mostly amyloid beta 1-40 and amyloid beta 1-42), but for historic reasons, the name was conserved.
Histologic dyes such as Congo Red or Thioflavin S or T show affinity for the amyloid plaques. Although they are commonly used for amyloid plaques detection, they come with several limitations, firstly in their spectral properties, with both having a broad range of excitation frequencies leading to a "bleed through" when illuminated with other filters and secondly by requiring harsh chemicals making it less compatible with subsequent use of antibodies.
Amylo-Glo RTD (Cat. No. TR-300-AG) is a new histological marker developed by Biosensis (Thebarton, South Australia) that shows clear superiority for visualising amyloid plaques over these conventional markers (Schmued et al., 2012).
- Amylo-Glo shows the same affinity as conventional probes (Congo red, ThioflavinS and Pan abeta 40) and is suitable to use with fresh, frozen, and formalin-fixed immunohistochemistry or cytochemistry.
- Amylo-Glo has a unique emission/excitation profile. Only excitable with UV light and emits a bright blue/yellow colour.
- Amylo-Glo only uses mild conditions making it ideal for subsequent immunohistochemistry labelling.
- Its chemical and spectral properties allow for multi-labelling studies. Its specific blue fluorescence contrasts effectively with red and green immunofluorescence labelling.
- Amylo-Glo is perfect for low magnification studies. Indeed, its unusual brightness (5-6 times brighter than conventional probes) allows to generate strong signals at extremely low magnification (x2).
This triple exposure allows for the simultaneous localization of Amylo-Glo® positive amyloid plaques (blue), GFAP positive hypertrophied astrocytes (green) and activated microglia (red) in the hippocampus of the AD/Tg mouse. Combined UV, blue and green light illumination.
Amylo-Glo UV illumination only
Biosensis Amylo-Glo RTD is also available with an ethidium bromide counter stain (Cat. No TR-400 AG) for a quick and effective way to visualise amyloid plaques as well cell nuclei and cell bodies of cells while under UV illumination in one step.
Both products are currently available to purchase in the UK and Ireland through Newmarket Scientific, the new distributor of Biosensis.
Reference:
Schmued L. et al, Journal of Neuroscience Methods 209 (2012), 120-126
Reference:
Schmued L. et al, Journal of Neuroscience Methods 209 (2012), 120-126
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