title: Use of limulus assay to compare the biological activity of peptidoglycan and endotoxin.
abstract: The gelation of a lysate prepared from the amebocytes of Limulus polyphemus, the horseshoe crab, has been used to detect endotoxin-like material in clinical studies and in "in vitro" experiments. The investigation of blood samples from 54 hospitalized patients suspected of having endotoxemia, revealed a positive limulus test in 14. Infections due to gram-positive organisms were not associated with positive assays. These results were in agreement with the observation that living gram-positive microorganisms - in contrast to gram-negative bacteria - did not initiate lysate gelation when studied "in vitro". Only very high concentrations of peptidoglycan, isolated from the cell walls of various gram-positive bacteria, induced the reaction. Therefore, these findings support the view, that the limulus test is relatively specific for the detection of gram-negative bacterial endotoxin and endotoxemia.
mesh_terms: D000818:Animals; D002176:Candida albicans / Q000276:immunology; D004731:Endotoxins / Q000032:analysis / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology; D006458:Hemolymph; D007709:Klebsiella / Q000276:immunology; D008722:Methods; D008837:Micrococcus / Q000276:immunology; D008974:Mollusca; D010325:Pasteurella / Q000276:immunology; D010457:Peptidoglycan / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology; D012706:Serratia marcescens / Q000276:immunology; D013210:Staphylococcus / Q000276:immunology; D013291:Streptococcus / Q000276:immunology
chemical_list: D004731:Endotoxins; D010457:Peptidoglycan