Figure 3: Functional characterization of hiPSC-platelets in vitro. (A) The four panels are representative dot plots for iPSC-platelets derived from feeder-free (FF) cultures or OP9 cultures binding to fibrinogen antibody in the absence (top) and presence (bottom) of ADP (50uM). Platelets derived from both FF and OP9 cultures show similar fibrinogen binding activity in response to platelet agonist stimulation. (B) FACS analysis of agonist-dependent surface marker expression of CD62P and PAC-1 upon different platelet agonists (e.g. ADP, Thrombin, AYPGKF peptide) from hiPSC-platelets derived from feeder-free culture condition. Increase binding of CD62P and PAC-1 was observed from activated platelets after agonist stimulation. All data represented here are from more than three independent experiments using two different human iPSC lines.