**6.1 Thioflavin T binding assay**

The use of Thioflavin T (ThT) and its derivatives is perhaps the simplest and most widely used method for monitoring the aggregation of amyloidogenic proteins. ThT is a low molecular weight dye exhibiting fluorescence emission when fibrillar protein aggregates bind to the β-layer groove structure. Traditionally, ThT has been used to detect amyloid fibrils because of the characteristic sigmoidal increase in fluorescence that occurs between the monomeric state and the ends of the fibrils [69, 70] beside ThT also binds to fibrillar aggregates containing β-sheet groove binding sites (fibrillar oligomers and fibrils). Prefibrillar aggregates of β-sheet structure contain few binding sites than fibril thereby showing low frequency of fluorescence [71]. Thus, ThT could indicate the presence of toxic circular fibrin and fibrin oligomers, but not the presence of pre-fibrin oligomers that do not have a clear β-sheet structure [72].
