The reaction, and presumed binding, of the hydrophobic LPS within fibrinogen fibres implies that they contain, or expose, significant hydrophobic elements. Such elements, also common in amyloid-like fibrils , can be stained fluorescently using dyes such as thioflavin T (ThT) . We therefore studied the effect of 0.2 ng l−1 LPS on the ability of the fibrin fibres formed following thrombin treatment of PPP to bind ThT (figure 4). In contrast with the LPS-free controls (figure 4a), there is a very substantial binding of ThT to the fibrin fibres formed in the presence of the LPS (figure 4b). The lipopolysaccharide binding protein (LBP) is a potent binder of LPS, and would therefore be expected to inhibit the amyloidogenic effects on blood clotting observed. Thus, we also studied the effect of 2 ng l−1 LBP and 2 ng l−1 LBP + 0.2 ng l−1 LPS mixture on ThT binding (figure 4c,d) . Figure 4.(a) Control PPP with ThT and thrombin and (b) as panel (a) but pre-incubated with 0.2 ng l−1 LPS; (c) as panel (a) but pre-incubated with 2 ng l−1 LBP; (d) as panel (a) but pre-incubated with 0.2 ng l−1 LPS and 2 ng l−1 LBP. (Online version in colour.)