Adherence of S. aureus to immobilized fibrinogen (A), fibronectin (B), and vWF (C). RN6390 wild type (WT), RN 6911 agr, ALC136 sar, and ALC135 agr sar S. aureus cells (2 × 108 CFU) were placed on polystyrene plates coated with fibrinogen (0.5 mg/ml), fibronectin (0.01 mg/ml), or vWF (0.25 U/ml) and incubated under static (light oscillation) or flow (200 s−1) conditions for 10 min at room temperature. Samples were washed, stained, and analyzed as described in Materials and Methods. Data are means ± SD for four to six determinations performed in duplicate. ∗, P < 0.01; ∗∗, P < 0.001 for mutants compared to the wild type.