Figure 3.

Screening for aggregation-inhibiting compounds via ThT assay. Each of the initial ten compounds was tested in a ThT screening to check if they had an aggregation-modifying effect on full-length tau 441. All compounds were mixed in a concentration of 50 µM with 50 µM recombinant full-length tau 441, 12.5 µM heparin, 500 µM DTT, 2% DMSO, and 20 mM ThT. Every well was adjusted to 100 µL with 1× PBS pH 7.4. Measurements were taken in intervals of 20 min. The plate was incubated at 37 °C and shaken for 15 s at 300 rpm before each measurement. The tau control did not contain any compounds, while the heparin negative control lacked both heparin and compounds. We chose 50 µM tau to allow de novo aggregation of tau to happen within days. We are fully aware that this is not a physiological concentration of tau. At about four days incubation time, measurement was prematurely terminated. Data recording was restarted without any time delay. The initial measurement points contained artefact signals that led to the spikes observed at about 4 days incubation.