List Labs provides endotoxin or lipopolysaccharides (LPS) for research and clinical investigation. This material has been extracted from bacterial cell walls of different strains of E. coli, Salmonella typhimurium and Salmonella minnesota. Several of the endotoxins have been further purified to remove traces of residual protein and nucleic acids, producing either the Ultra Pure or HPTTM. Contact us for more information about E. coli O113, extracted at high purity and under GMP conditions for use in clinical trials: GMP ListTM HPTTM LPS.

LPS structure may be generally described as three linked regions. The first structural feature is the lipid component called Lipid A, primarily responsible for the effects of endotoxin. Linked to Lipid A is the core antigen or R polysaccharide, a short chain of sugars including 2-keto 3-deoxyoctonate (KDO). The third structural feature is attached to the core polysaccharide and is more elaborate, containing up to 40 repeating subunits of 3 to 5 sugars, referred to as the O antigen, O side chain or O polysaccharide. Variations in the composition of the O antigen account for different antibody responses to bacteria species. Lipid A, acting alone or as a component of LPS, is a potent modulator of the mammalian immune response. The presence of Lipid A or LPS in mammalian macrophages or endothelial cells triggers a signaling cascade leading to the secretion of pro-inflammatory cytokines and nitric oxide. LPS also acts as a B cell mitogen.

To follow is a list of LPS available for purchase, sorted by the bacteria stains from which it was derived. Find also on this list, monophosphoryl Lipid A (MPLA) prepared from Salmonella minnesota R595 (Re). All LPS sold by List Labs has been made in the USA.