Lipopolysaccharides from Escherichia coli 0111:B4, FITC conjugate

Application

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).

FITC-Lipopolysaccharides (FITC-LPS) may be used to study processes such as the movement/transport of LPS across tissue barriers such as the colonic epithelium and cellular binding and internalization of lipopolysaccharides with fluorescence-based assay systems. It may be used to evaluate, qualify and quantify lipopolysaccharides (LPS) removal reagents and procedures. FITC-LPS conjugate may be used for the detection of LPA binding proteins and motifs.

Biochem/physiol Actions

Lipopolysaccharides (LPS) are localized in the outer layer of the membrane and are, in noncapsulated strains, exposed on the cell surface. They contribute to the integrity of the outer membrane, and protect the cell against the action of bile salts and lipophilic antibiotics.

Preparation Note

The product is soluble in water (5 mg/ml) yielding a hazy, yellow to orange solution. 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. For cell culture use, LPS should be reconstituted by adding 1 ml of sterile balanced salt solution or cell culture medium to a vial (1 mg) and swirling gently until the powder dissolves. Solutions can be further diluted to the desired working concentration with additional sterile balanced salt solutions or cell culture media.