Plotting ∆D versus ∆F, which is commonly used to obtain structural information of adsorbed molecules , clearly demonstrates that HsP binding is characterized by a single phase, fibril growth features two phases (injection perturbation and fibril growth) and the mixture of HsP and α-synuclein shows three distinct phases (injection perturbation, HsP binding dominated phase and fibril growth dominated-phase). The fibril growthdominated phase is characterized by a linear correlation between ∆D and ∆F. The ∆D-∆F slope in both conditions are similar (-0.20 10 -6 /Hz ± 0.001 for pure α-synuclein and -0.21 10 -6 /Hz ± 0.0003 for α-synuclein + HsP), showing that the measurement is dominated by the same type of material deposition in these phases. As such we can conclude that the dissipation response of the HsP + α-synuclein incubation, which is constant throughout the entire measurement, reports almost exclusively on the addition of fibrillar material. The ∆D/∆F relationship can be plotted in the time-domain from the numerical derivatives, which provides insight into the duration of each of the phases. From this analysis we find that the pure α-synuclein incubation reports truthfully on fibril growth approx. 200 s after the start in the injection. The HsP + α-synuclein converges to pure fibril growth after 5 minutes of incubation.