a) P1 detects both misfolded oligomers and insoluble aggregates. Whereas, P18 should only detect insoluble aggregates. b) Diagram of the AggTag method. POI: protein-of-interest, P: AggFluor probes. c) Structure of the P1h and P18h. d) Fluorescence and turbidity kinetics of heat-induced SOD1-A4V-Halo aggregation at 59°C, 25 μM proteins and 5 μM probes. e) TEM images of SOD1-A4V-Halo aggregates reveal large tightly packed structures (59°C, 25 μM proteins, 20 min).