Quality evaluation of commercial anti-Salmonella antibodies for immunomagnetic separation using whole-cell dot blot

Abstract

The selection of antibodies with the desired specificity, immunoreactivity, purity and integrity is a key step in developing an effective immunosorbent for immunomagnetic separation (IMS). The choice of methods for characterizing the antibodies is limited, especially with antibodies specific to surface cell structures. In this study, four commercial anti-Salmonella antibodies were evaluated from the point of view of their immunoreactivity with the cells of Salmonella Typhimurium and of their purity. For these purposes, traditional SDS-PAGE analysis with subsequent silver staining and a newly adapted whole-cell dot blot technique were applied. Based on this testing, monoclonal anti-core LPS Salmonella antibodies from MyBiosource unambiguously demonstrated the highest immunoreactivity to Salmonella Typhimurium cells, whereas cross-reactivity with the closely related G- bacteria, Escherichia coli and Citrobacter braakii was not observed. Such antibodies will be subsequently used for the preparation of an anti-Salmonella immunosorbent and applied in IMS. The immunoreactivity and selectivity of anti-Salmonella poly- and monoclonal antibodies are also discussed.