oxLDL promotes procoagulant PSer exposure. To detect exposed PSer, fluorophore-tagged annexin V or lactadherin binding to washed human platelets (1 × 10⁸/mL) was measured by flow cytometry. Representative dot plots of annexin V binding to platelets stimulated with PBS, 50 μg/mL LDL or oxLDL for 15 minutes (A). Percent (%)-positive platelet staining with annexin V after exposure to PBS, 50 μg/mL or 100 μg/mL LDL or oxLDL (B), percent-positive staining with lactadherin up to 30 minutes with 50 μg/mL oxLDL (C) and oxLDL pretreatment followed by a low or high dose of classic agonists (D). Data represented as mean ± standard error of the mean (SEM). P value was determined by 1-way analysis of variance (ANOVA) with Tukey posthoc analysis in panel B or Dunnet post hoc analysis in panel C. P value was determined by 2-way ANOVA with Tukey post hoc analysis in panel D. N = 5 different donors in panel B, 3 different donors in panels A and C, and 4 different donors in panel D.