What is Thioflavin T fluorescence?
Thioflavin T (ThT) dye fluorescence is used regularly to quantify the formation and inhibition of amyloid fibrils in the presence of anti-amyloidogenic compounds such as polyphenols.
What is the difference between Thioflavin T and S?
Thioflavin S Like thioflavin T it binds to amyloid fibrils but not monomers and gives a distinct increase in fluorescence emission. However unlike thioflavin T, it does not produce a characteristic shift in the excitation or emission spectra.
How do you dissolve Thioflavin T?
Thioflavin T (ThT) is prepared by dissolving ~3 mg dry powder in 1 mL water. The solution is filtered through 0.22 μm syringe filters followed by measurement of the concentration by diluting the stock solution in ethanol and using an extinction coefficient of 26,620 M-1 cm-1 at 416 nm.
What are amyloid fibrils made of?
Amyloid fibrils are formed by normally soluble proteins, which assemble to form insoluble fibers that are resistant to degradation. Their formation can accompany disease and each disease is characterized by a specfic protein or peptide that aggregates.
What does Thioflavin S stain for?
Congo Red and Thioflavin S are the two major histological stains used to detect any form of amyloid. These dyes bind to the characteristic β-pleated sheet conformation of amyloid.
How does Congo red stain amyloid?
Staining with CR Amyloid is detected by the increased optical anisotropy after CR binding [57], which is called the ‘apple-green birefringence’ (under crossed polarisers) [58]. ‘Apple-green birefringence’ is used to detect amyloid deposits in tissues and in in vitro studies of amyloids [15,57,58].
How is Thioflavin S solution prepared?
Hi Kaustuv, Preparation of Thioflavin T (ThT): Prepare 10 mM ThT stock (Dissolve 31.8 mg of ThT in 10 ml of Tris buffer, pH 8.0). Add 5% sodium azide (NaN3) to this solution so as the final NaN3 concentration is 0.01%. The solution is freshly prepared and filtered through 0.2 micron sterile syringe filter before use.
How do you make a congo red stock solution?
Preparing the solutions for staining Congo Red powder dye solution (for staining acc. to the Highman method): 1% solution of Congo Red powder dye: • Dissolve 0.5 g of Congo Red dye in 50 ml of distilled/demi water. Add 50 mL of 100% ethanol. Filter before use.
What is the function of fibrils?
Collagen fibrils are the major mechanical component in the extracellular matrix of a broad range of multicellular animals from echinoderms to vertebrates where they provide a stable framework for tissues.
What are amyloid fibrils what biological functions are these known to perform?
Amyloids are highly ordered cross-β sheet protein aggregates associated with many diseases including Alzheimer’s disease, but also with biological functions such as hormone storage. The cross-β sheet entity comprising an indefinitely repeating intermolecular β sheet motif is unique among protein folds.
Which stain is used for amyloid deposits?
Alkaline Congo red stain
Alkaline Congo red stain is the most commonly used stain of amyloid.
How does Congo red staining work?
The Congo red staining principle is based on the formation of hydrogen bridge bonds with the carbohydrate component of the substrate. Congo red is an anionic dye and is capable of depositing itself in amyloid fibrils, which then exhibit a conspicuous dichroism under polarized light.