Analytical Methods
Endotoxin Testing
Definition
Endotoxin testing is an analytical quality control procedure used to detect and quantify bacterial endotoxins (lipopolysaccharides, LPS) shed from the outer membrane of Gram-negative bacteria. The Limulus Amebocyte Lysate (LAL) assay is the gold standard method, utilizing a clotting cascade from horseshoe crab blood cells that is activated by endotoxin. Endotoxin contamination in research peptides can confound experimental results by activating innate immune responses and inducing pyrogenic reactions. Peptides intended for in vivo research typically require endotoxin levels below 5 EU/kg body weight.