The SensoLyte« ThT β-Amyloid (1-40) Aggregation kit provides a convenient and standard method to measure Aβ40 aggregation using Thioflavin T dye. Aβ40 peptide is pretreated to ensure it is in a monomeric state. An optimized fibrillation buffer is included with the kit, and two known inhibitors are supplied as controls. The assay is based on the property of ThT dye in which fluorescence (Ex/Em=440/484 nm) is increased when bound to aggregated Aβ peptides. Alzheimer's disease (AD), the most common cause of dementia, is characterized by the presence of senile plaques and neurofibrillary tangles, surrounded by damaged neurons. Beta-Amyloid (Aβ) peptides, Aβ40 (1-40) and Aβ42 (1-42), were found to be a major component of the above plaques. Many studies suggest that these peptides can form toxic oligomers and fibrils under physiological conditions and rapidly aggregate. Since Aβ aggregation is evidently an essential event in the pathogenesis of AD, a reliable assay is important to study Aβ fibrillation kinetics and screen for Aβ aggregation inhibitors.
Figure 1. An increase of fluorescence signal is correlated with an increase of Aβ40 fibril formation. Phenol Red, Morin, Rhodamine B, and Tannic Acid were added at 50 μM final concentration to inhibit Aβ40 aggregation. Fluorescence signal was monitored at Ex/Em= 440/484 nm every 5 minutes at 37║C with 15 seconds shaking between reads (Flexstation II-384 fluorimeter, Molecular Devices).