LPS, from Escherichia coli O55:B5

LPS, from E. coli O55:B5 is an S (smooth) type lipopolysaccharide endotoxin extracted from Escherichia coli O55:B5. It consists of three parts: O antigen, core oligosaccharide, and lipid A. It is an important component of the outer membrane of the cell wall of Gram-negative bacteria and a typical TLR4 agonist, with well-defined pyrogenicity and serotype specificity. This LPS can strongly activate the TLR4 signaling pathway in immune cells, triggering a cascade release of cytokines and inflammatory mediators, and inducing in vitro cell activation, inflammatory responses, and endotoxin-like shock responses. It is a classic stimulant for studying endotoxin and inflammatory mechanisms. With stable activity and reproducible responses, it is suitable for evaluating the role of endotoxin in various inflammation-related pathological processes, such as liver diseases, nerve injury, and skeletal muscle insulin resistance. It is commonly used to establish in vitro inflammatory models in monocytes/macrophages, endothelial cells, and immune cells (such as detecting NO, cytokines, and NF‑κB/ MAPK activation), as well as to construct acute inflammation, sepsis, and organ injury models in mice or other animals in vivo; it can also be used as a positive control for endotoxin (LAL) detection and for screening the effects and mechanisms of anti-inflammatory/immunomodulatory drugs.