Description_x000D_ General description_x000D_ Lipopolysaccharides (LPSs) are characteristic components of the cell wall of Gram-negative bacteria. A typical LPS molecule has lipid A (a glucosamine-based phospholipid), a relatively short core oligosaccharide and a distal polysaccharide (O-antigen). LPSs contribute to the integrity of the outer membrane, and protect the cell against the action of bile salts and lipophilic antibiotics. They stimulate host cells via TLR2 and TLR4 (toll like receptors). This stimulation results in the generation of various proinflammatory cytokines, such as TNFα (tumor necrosis factor), IL-1 (interleukin 1) and IL-6._x000D_ This product is phenol extracted from Escherichia coli serotype O111:B4. The source strain is from a private collection. This LPS serotype has been used to stimulate B-cells and induce NOS (nitric oxide synthase) in human hepatocytes._x000D_ Application_x000D_ Lipopolysaccharides (LPSs) from Escherichia coli O111:B4 have been used for the stimulation of macrophages. They have been used for LPS preconditioning in mice._x000D_ Lipopolysaccharides (LPSs) are characteristic components of the cell wall of Gram-negative bacteria. LPS and its lipid A moiety stimulate cells of the innate immune system by the Toll-like receptor 4 (TLR4), a member of the Toll-like receptor protein family, which recognizes common pathogen-associated molecular-patterns (PAMPs)._x000D_ Packaging_x000D_ 10, 25, 100 mg in poly bottle_x000D_ Preparation Note_x000D_ The product is soluble in water (5 mg/ml) or cell culture medium (1 mg/ml) yielding a hazy, faint yellow solution. A more concentrated, though still hazy, solution (20 mg/ml) has been achieved in aqueous saline after vortexing and warming to 70-80 oC. Lipopolysaccharides are molecules that form micelles in every solvent. Hazy solutions are observed in water and phosphate buffered saline. Organic solvents do not give clearer solutions. Methanol yields a turbid suspension with floaters, while water yields a homogeneously hazy solution.