Purification of B. pseudomallei OPS Antibodies

To facilitate purification of specific antibodies against B. pseudomallei OPS, type A LPS was extracted from the select agent excluded strain B. pseudomallei RR2808 using a modified hot phenol method (37 (link), 38 (link)). Purified OPS antigens were then obtained by acid hydrolysis and size exclusion chromatography essentially as previously described (37 (link), 39 (link)). The OPS was then oxidized with sodium metaperiodate as previously described (37 (link)) and conjugated to UltraLink Hydrazide resin (Thermo Scientific, USA) via reductive amination following the manufacturer’s instructions. The resulting OPS-coupled resin was stored at 4°C until use.