Lipopolysaccharide (LPS)

Overview

Lipopolysaccharides, abbreviated as LPS, are a unique component of the cell wall of Gram-negative bacteria, located on the outermost layer of the cell wall and exposed on the surface of non-capsulated bacteria. They are beneficial for maintaining the integrity of the outer membrane and protecting bacteria from the destruction of bile salts and lipophilic antibiotics. Structurally, lipopolysaccharides consist of lipid A, core polysaccharide, and O-polysaccharide side chains. Lipid A is the main component of bacterial endotoxins and determines the strength of its toxicity; the O-polysaccharide side chains are highly variable among different bacteria, specifically determining the serotype of the bacteria. This product originates from the serotype Escherichia coli O55:B5, extracted by the phenol method. Its endotoxin level is no less than 500,000 EU (endotoxin units)/mg. Analytically, 1ng is equivalent to 0.5EU (limulus amebocyte lysate method) and 10EU (chromogenic method). LPS O55:B5 can be used to stimulate the activity of human peritoneal macrophages (1ng/ml) and equine peritoneal macrophages (1-100ng/ml).