A) For assembly inhibition, 100 µM aza 9 was incubated with 2 µM tau for 20 minutes before the addition 0.6 µM heparin. 16 hours after induction, the degree of aggregation was determined using the filter trap assay detected by a mixture of antibodies to normal tau (Tau 5, Tau 7 and Tau 12), an antibody to oligomeric tau (TOC1) and an antibody to a toxic conformation of tau (TNT1). The average of three independent trials ± SD is shown for no compound controls (white bars) and 100 µM aza 9 (black bars). B) 2 µM tau and 0.6 µM heparin were incubated together for 21 hours prior to the addition of 100 µM aza 9 or an equal volume of DMSO. Disassembly reactions proceeded for an additional 12 hours and the degree of aggregation was determined using the filter trap assay detected by a mixture of antibodies (Tau 5, Tau 7 and Tau 12), TOC1 and TNT1. The average of three independent trials ± SD is shown for no compound controls (white bars) and 100 µM aza 9 (black bars). *P ≤ 0.05; ** P ≤ 0.01; *** P ≤ 0.001.