INU1-induced CLEC-2 internalization in fetal liver–derived MKs. The livers of 13.5- to 14.5-day-old mouse embryos were isolated from time-mated mice and a single-cell suspension was cultured for 72 hours; mature MKs were enriched on day 3 of culturing using a bovine serum albumin density gradient. These MKs were treated with INU1-F488 for the indicated time points. Subsequently, they were spun onto glass slides, fixed, and stained with α-rat IgG-Cy3 under (B) permeabilizing or (A) nonpermeabilizing conditions, as well as with phalloidin-F647 (red) diluted in permeabilizing buffer. Nuclei were stained using DAPI. Samples were visualized with a Leica TCS SP5 confocal microscope. Scale bar represents 10 µm.