Background-corrected movie of the early growth stage of platelets with sizes below the diffraction limit (scale bar: 3 µm). 50 µL of 2.51 nM (0.1 µg/mL) seed solution was spin-coated onto a cleaned coverslip twice (3200 rpm for 50s followed by 4000 rpm for 30s). PCL 45 :PCL 45 -b-PDMA 348 mixtures in THF were then diluted with methanol to achieve a final concentration of 0.35 µM (3.33 µg/mL). 150 µL of unimer methanol solution was added onto the seed-coated surface and iSCAT observation started immediately. A laser power density of 4 µW µm -2 at 637 nm, a camera exposure time of 400 µs, and an overall time-lapsed frame rate of 10 s -1 were chosen. This movie corresponds to the data in Fig. and.