LPS binding to normal platelets in vitro, saturability, and kinetics. (A) PRP from a healthy donor incubated with O157LPS at 1 μg/mL and stained with anti-O157LPS. Platelet aggregates are visible by immunofluorescence. (B) Same as for panel A, labeled with CD41-PE to identify platelets. (C) Untreated platelets (PRP) from a healthy donor labeled with anti-O157LPS antibody. (D) Same as for panel C labeled, with CD41-PE. No aggregates are visible. (E) Results of a representative experiment of PRP from a healthy donor incubated with LPS (1 μg/mL) showing O157LPS binding to 75% of the platelet population (filled) compared with the control antibody (open). (F) Saturability was obtained at an O157LPS concentration of approximately 1 μg/mL. Vertical lines denote the standard deviation. (G) Kinetics of O157LPS binding to platelets showing that maximal binding was achieved after 30 minutes' incubation and did not decrease within 2 hours.