What is ThT fluorescence?
Thioflavin T (ThT) is a commonly used probe to monitor in vitro amyloid fibril formation. Upon binding to amyloid fibrils, ThT gives a strong fluorescence signal at approximately 482 nm when excited at 450 nm [2]. It has long been recognized that ThT can be used to quantify amyloid fibrils [12].
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.
What does Thioflavin stain?
Since its first description in 1959, the fluorescent dye Thioflavin-T (ThT) has become among the most widely used “gold standards” for selectively staining and identifying amyloid fibrils both in vivo and in vitro.
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 is ANS fluorescence?
8-anilino-1-naphthalenesulfonic acid (ANS) is an extensively utilized fluorescent probe for the characterization of protein binding sites. ANS is often considered a non-fluorescence probe when bound to the exposed binding sites of proteins.
What is Congo red assay?
Staining with Congo Red (CR) is a qualitative method used for the identification of amyloids in vitro and in tissue sections. However, the drawbacks and artefacts obtained when using this dye can be found both in vitro and in vivo.
What is Congo red dye?
Congo Red is the sodium salt of benzidinediazo-bis-1-naphthylamine-4-sulfonic acid; a diazo dye that is red in alkaline solution and blue in acid solution and used especially as an indicator and as a biological stain. NCI Thesaurus (NCIt) Congo Red is an indicator dye that is blue-violet at pH 3.0 and red at pH 5.0.
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.
How does ThT bind to amyloid?
Thioflavin T is a benzothiazole dye that exhibits enhanced fluorescence upon binding to amyloid fibrils and is commonly used to diagnose amyloid fibrils, both ex vivo and in vitro. This suggests that positive charge on the thioflavin T molecule has a role in its micelle formation that then bind the amyloid fibrils.
What are Protofibrils?
Abstract. Protofibrils of the 42 amino acids long amyloid-β peptide are transient pre-fibrillar intermediates in the process of peptide aggregation into amyloid plaques and are thought to play a critical role in the pathology of Alzheimer’s disease.
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.
What is ANS in biochemistry?
8-Anilinonaphthalene-1-sulfonic acid (ANS), also called 1-anilino-8-naphthalenesulfonate, is an organic compound containing both a sulfonic acid and an amine group. This compound is used as a fluorescent molecular probe.