Background-corrected movie of platelet growth recorded with high speed (scale bar: 2 µm). 50 µL of 2.51 nM (0.1 µg/mL) seed solution was spin-coated onto the cleaned coverslip twice (3200 rpm for 50 s followed by 4000 rpm for 30 s). PCL 45 :PCL 45 -b-PDMA 348 mixtures in THF were then diluted with methanol to achieve final concentration of 0.29 µM (2.78 µg/mL). 150 µL unimer methanol solution was added onto the seed-coated surface and iSCAT observation started from the mid-stage of platelet growth. A laser power density of 24 µW µm -2 at 637 nm, a camera exposure time of 80 µs, and an overall time-lapsed frame rate of 3000 s -1 were chosen. This movie corresponds to the data in Fig. and H.