Reactivity of anti-rHpuA and anti-rHpuB antisera with HpuAB in meningococcal lysates.

<p>Meningococcal cells of strain 8047, an isogenic Δhpu mutant and two phase variants of a carriage strain (N88.1, hpu-OFF; and N272.1, hpu-ON) were grown to mid-log (OD600 = ~0.5) before 30 μM of desferal was added to produce iron-limited conditions. Cultures were also grown concurrently in iron-replete conditions. All cultures were incubated for two hours before heat-inactivation at 56°C overnight. Lysates were prepared using an equal number of OD units and subject to SDS-PAGE electrophoresis and Western blotting. Blots were then probed with 1:500 dilutions of mouse polyclonal sera followed by a 1:2000 dilution of an anti-mouse IgG HRP-conjugate:- upper panel, anti-rN88-HpuA; middle panel, anti-r8047-HpuA; lower panel anti-r8047-HpuB. Lysates were from:- strain N88.1, induced (lane 1); 8047ΔhpuAB, induced (lane 2); wild-type 8047, uninduced (lane 3); wild-type 8047, induced (lane 4); N272.1 uninduced (lane 5); and N272.1 induced (lane 6).