Tau aggregation in HEK 293 Tau expressing cells treated with 3-APS. Detergent insoluble aggregates of Tau were isolated from HEK 293 tau cells untreated (control) or treated with 3-APS. The detergent insoluble material (see methods) was analyzed by western blot using an antibody against Tau (ab 7.51). Reaction of the unfractionated cell extract with β-actin antibody, was used as loading control. The average of at least three separate determinations is indicated. *, P < 0.05, **, P < 0.01 compared with control (Student's t test).