CHEMBL3889073

Competitive Binding Assay: For tau imaging probes other than THK-5105, binding to K18-ΔK280 aggregates was evaluated with a competitive binding test using [18F] THK-5105 as a radioactive competitor. In the binding test, [18F] THK-5105 (at a final concentration of 1.76 nM) and a tested compound (at final concentrations of from 0.1 to 1000 nM) coexisted in the reaction system, to which K18-ΔK280 aggregates (at a final concentration of 200 nM) was then added and the mixtures were incubated at room temperature for one hour. The radioactivity of [18F] THK-5105 binding to the aggregates was determined in a similar way as in the saturation binding test of THK-5105. The percentage of [18F] THK-5105 bonding in the absence of each tested compound was set to be 100%, and percentages of [18F] THK-5105 bonding at various concentrations of each of the tested compounds were determined.