Cytofluorimetric evaluation of H₂O₂ production in DCFH-DA–loaded platelets. (A) Fluorescence peak of unstimulated platelets. (B) Fluorescence peak of unstimulated platelets with 250 U/mL of catalase (absence of fluorescence). (C) Shift of fluorescence after incubation with H₂O₂ (1 mmol/L). (D) Shift induced by collagen 50 μg/mL. (E) Effects of the same dose of collagen in GFP treated with catalase (500 U/mL). (F) Effects of the same dose of collagen in GFP treated with catalase (1,000 U/mL). Results are representative of five separate experiments.