N hydroxysuccinimide

A rabbit polyclonal antibody with specificity to C. jejuni was sourced from MARDI (the Malaysian Agricultural Research and Development Institute), Malaysia. Goat F(ab) anti-rabbit IgG H&L (ab6824) were purchased from Abcam Ltd., UK. N-hydroxysuccinimide (NHS) were sourced from Thermo Scientific, UK. 11-mercaptoundecanoic acid (11-MUDA), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), ethanolamine hydrochloride, ethanol, hydrochloride acid (HCl), sodium acetate, PBS (phosphate buffered saline tablet, pH 7.4), hydrogen peroxide (H₂O₂), sulfuric acid (H₂SO₄), bovine serum albumin (BSA) were purchased from Sigma-Aldrich, UK. All methods were carried out in accordance with relevant guidelines and regulations. All experimental protocols were approved by the Malaysian Agricultural Research and Development Institute and Cranfield University, and carried out in accordance with the relevant guidelines and regulations.

Fluorescent microparticles (500 nm), 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) were purchased from Thermo Fisher Scientific (Waltham, MA). Polystyrene carboxylate magnetic particles (292 nm) were purchased from Ademtech (Pessac, France). Magnets for capturing magnetic particles were from Dexter Magnetic Technologies (Elk Grove, IL). Microtiter plates (96 well clear bottom, half area black plate) were from Greiner Bio-One (Monroe, NC). Native Toxin B standard purified from C. difficile (ribotype 087) was purchased from List Laboratories (Campbell, CA). Mouse monoclonal antibodies raised against C. difficile toxin B were from BBI Solutions (Cardiff, UK) and Fitzgerald (Acton, MA). Bovine serum albumin (BSA), Casein, Trizma® base, Trizma®-HCl, Triton X-100 and OptiPrep were from Sigma-Aldrich (St. Louis, MO). Direct Black 19 was from Orient Corporation (Cranford, NJ). Protease inhibitor cocktail was from Takara Bio (Mountain View, CA).

β-glucan (m.w. 179,000) obtained from barley (low viscosity) was purchased from Megazyme (Ireland). DHA (m.w. 328.57) was purchased from Nu-Check Prep, Inc. (Elysian, MN, USA). Simulated gastric fluid with 0.2% NaCl in 0.7% (v/v) HCl, Acetate Buffer (1 M, pH 4.0), N-(3-Dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC), N-Hydroxysuccinimide (NHS), and simulated intestinal fluid were purchased from Thermo Fisher Scientific (Waltham, MA, USA). Mucin from porcine stomach type II was purchased from Sigma Aldrich (Burlington, MA, USA). 1 M Glycine–HCl Buffer, pH 2.7 ± 0.1, 10X Concentrate was purchased from Polysciences, Inc. (Warrington, PA, USA). DiR (DiIC18(7); 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide) was purchased from Perkin Elmer (Waltham, MA, USA).