Analysis of Salmonella lipopolysaccharides by sodium deoxycholate-polyacrylamide gel electrophoresis

Lipopolysaccharides (LPSs) were analyzed by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium deoxycholate (DOC) or sodium dodecyl sulphate (SDS) and the results obtained compared. Two-dimensional PAGE of the S form of LPS revealed that, with SDS, bands which appeared to be single after the one-dimensional experiment were resolved into several bands after two-dimensional electrophoresis. In the presence of DOC, however, a diagonal of single bands was obtained in one-dimensional electrophoresis indicating optimum resolution. The high quality of resolution by DOC-PAGE was constant for amounts of LPS up to 20 micrograms. Finally, DOC-PAGE does not require boiling of the samples in DOC, which may be an advantage over SDS-PAGE.