FIG. 2.

Binding of polymyxin B by LPSs from different Brucella strains. LPS suspensions adjusted to 60 to 63 nM concentrations of lipid A were incubated with a 13.75 μM concentration of dansyl-polymyxin B, and the fluorescence was estimated at a range of 400 to 600 nm. The inserted table shows the binding of different concentrations of dansyl-polymyxin B of the different LPSs at 480 nm. Dansyl-polymyxin B alone did not produce detectable fluorescence under these conditions. RFU, relative fluorescence units.