Figure 4: Comparison of platelets generated from human iPS cells (hiPSCplatelets) and human peripheral blood platelets. (A) A platelet gate was fixed based on the forward- and side-scatter profiles of human peripheral blood platelets (left). 99% of the gated particles were CD42b+ and CD61+ (right) from human blood platelets. (B) The two panels show a flow cytometry FSC vs SSC profile (left) from hiPSC-derived platelets using the same platelet gate. Approximately 12% of hiPSC-PLTs expressed both CD42b and CD61. (C-E) FACS measurements of fibrinogen binding activity of hiPSC-derived platelets compared to human blood platelets: (C) Comparison of fibrinogen binding shifts upon different platelet agonist stimulation from hiPSC-derived platelets and human platelets. (D) In human blood platelets: A dramatic binding of fibrinogen and CD61 to activated platelets was observed after agonist stimulation. (E) In hiPSC-derived platelets: A moderate binding of fibrinogen and CD61 to activated hiPSC-platelets was observed after agonist stimulation.The FACS results represented here were chosen from three independent experiments.