Example 11
A 20 μl bed volume of protein A beads (POROS® MabCapture™, Applied Biosystems®, CA, USA) was washed twice in 1 ml PBS by centrifugation (300 g, 1 min) and removal of the supernatant. Beads were coated with antibody by incubating beads with 10 μg antibody in 0.2 ml PBS for 30 minutes and 30 rpm at room temperature. Beads were washed again twice in 1 ml PBS and beads were taken up in 0.4 ml supernatant of a LB overnight culture of A. baumannii. Supernatant was prepared by centrifugation of the bacterial culture at >4000 g for 5 minutes and supernatant was filtered through a 0.2 μm filter for syringes (Nalgene #194-2520). The mixture was incubated for 1 h and 30 rpm at room temperature. Beads were washed again twice in 1 ml PBS. Finally, beads were resuspended in 30 μl lysis buffer for NuPAGE® 4%-20% Bis-Tris gels (NP0322BOX, Invitrogen) and incubated at 98° C. for 5 min. The sample was tested for presence of native FimA by immunoblot analysis as described above according to the manufacturer's instructions for denatured, reduced 4%-20% Bis-Tris gels using MES running buffer (IM-8042 Version H, Invitrogen). Rabbit immune serum against FimA was used for detection of FimA.
Results are shown in