Figure 4. Macromolecular crowding with Ficoll abolishes the heterogeneity of IAPP phase separated and aggregated system at the AWI.

(A) In presence of Ficoll, IAPP aggregate accumulation at the AWI is homogeneous. 3.6 μM IAPP–0.4 μM bIAPP–0.08 μM avidin D fluorescein was incubated with 6% Ficoll in a well of a 96-well plate. The well was imaged, z stacks encompassing the AWI and an area spanning 1417 × 1417 μm² were collected for at least 15 h. 3D projections were performed in Imaris and visualised with the AWI at the front facing the experimentalist and the bulk solution behind it. Presented are snapshots of 3D projections at relevant time points for three replicates. See also Supplementary Movie S3. (B) Tracking of the aggregates and their trajectories were performed for reactions described in (A). Shown are aggregate trajectories for three replicates. (C) Ficoll abolishes the system heterogeneity, in particular before gelation started. For the reactions described in (A), the speed of aggregates was calculated, along with that of the mean flow. Shown are the aggregate speed with that of mean flow subtracted overtime (top panel). The insets show a zoom up of early time points. The duration of aggregate mobility has been calculated from the top panel and is depicted at the bottom left. The coefficient of variation (standard deviation over mean) as a function of time is also shown (bottom right), i.e. to depict the variation between the reactions. Error bars represent ± SEM.