Lipopolysaccharides (LPS) are specific endotoxins that serve as a major component of the cell walls in gram-negative bacteria. Composed of Lipid A, a core oligosaccharide, and an O-specific polysaccharide, LPS strongly stimulates the immune system by binding to Toll-like receptor 4 (TLR4) on immune cells, triggering inflammatory responses. In most Salmonella serotypes, the LPS features a complex O-antigen (OAg) structure, with core oligosaccharide OAg units ranging from 16 to over 100 repeats. Mutations in OAg regulatory factors can alter the OAg structure, affecting Salmonella interactions with epithelial cells. Strains with long OAgs show increased translocation and invasion by SPI1-T3SS effector proteins, while strains lacking OAg entirely exhibit increased invasiveness and adhesion. This product is derived from Salmonella enterica serotype minnesota and is utilized for studies on host immune activation and its roles in inflammation and immune modulation.