, USA) were coated with 100 μL of washed bacteria (both MAP and MAA; 1 × 108 cfu/mL), diluted in sodium bicarbonate buffer

pH 9.6 for 60 min at room temperature, while shaking at 300 rpm on a electronic click here MTS shaker (IKA Werke, Germany). All subsequent incubations were performed for 30 min shaking at room temperature. After each incubation step, plates were washed three times with PBS containing 0.01% Tween 20. The secondary antibody was goat anti-Mouse (GAM)-PO (Roche, the Netherlands) 1:2000. Peptide ELISA was used for the initial epitope mapping of the monoclonal antibodies generated against MAP Hsp70. The peptide ELISA using cys-linked peptides has been described previously [23]. The different cys-linked peptides were diluted in 0.1 M Tris–HCl, pH 8.0 at a concentration of 15 μg/mL, and 100 μL was added at each well. To study Y 27632 whether monoclonal antibodies bind to intact bacteria, indicative of the presence of MAP Hsp70 in the bacterial cell wall, suspensions of MAA strain D4 and MAP strain 316F (generous gifts from D. Bakker, CVI) were prepared from log phase liquid cultures. Suspensions of MAA and MAP (both 1010 bacteria/mL in PBS) were diluted 1:100, washed three times by centrifugation (1 min at 14,000 RPM in an

Eppendorf centrifuge (Eppendorf, Germany)) and resuspended in PBS. These suspensions were diluted 1:100 in PBS supplemented with 1% BSA and 0.01% sodium azide (both from Sigma Aldrich, USA) and divided in volumes of 100 μL. The Hsp70 specific monoclonal antibodies were added in a concentration of 5 μg/mL. After incubation for 25 min at room temperature (RT) and three washes with PBS supplemented with 1% BSA and 0.01% sodium azide (FACS buffer), FITC-labelled Goat anti-mouse antibodies (Becton-Dickinson, USA) were added and incubated for 25 min at RT. After three more washes, 10,000 bacterial cells were used for analysis by FACScan (Becton-Dickinson,

USA). Multiplex peptide specific antibody measurements were performed using biotinylated peptides linked to avidin coated fluorescent microspheres (LumAv, Luminex, USA) on a Luminex 100 platform according to instructions all provided by the manufacturer (Luminex). A total of 2.5 × 105 beads (100 μL) per uniquely labelled beadset were washed twice with PBS, and subsequently incubated with 10 μmol biotinylated peptide for 10 min at 20 °C. After two washes with PBS, the beads were resuspended in their original volume (100 μL) using PBS supplemented with 1% bovine serum albumine (Sigma Aldrich, USA) and 0.01% sodium azide, and stored in the dark at 4 °C until further use. For multiplex analysis 20 μL of resuspended coated beads of each of up to 20 unique beadsets were pooled in an eppendorf container. To the final volume of beads, the same volume of PBS was added, and mixed. In a round bottom 96 well microtiter plate, 10 μL of the mixed beads was added per well. Subsequently, 100 μL of goat or calf serum per well was added.